Docs: update tooling and outdated/broken content

* Update docs build config
  * Specify Sphinx and theme versions in docs/requirements.txt
    (tox had been using latest; RTD had pinned older versions)
  * Update docs builds for Python 3 and recent Sphinx
  * Remove obsolete sphinx-rtd-theme patches
  * Add .readthedocs.yml
  * Move some JS to async (now that Sphinx supports that)
  * Fix version-alert.js for async loading
* Remove docs versionadded/changed info older than v3.0
* Fix broken GitHub issue links in changelog (never worked?)
* Add setup long_description_content_type
* Drop poorly maintained AUTHORS.txt 
  (just point to GitHub contributors page)

docs/_readme/template.txt

@@ -1,20 +1,25 @@
 %(head_prefix)s
 <!--
-  This approximates PyPI.org project page styling as of 8/2019
-  (and relies on their compiled CSS that was available at that time).
+  This approximates PyPI.org project page styling as of 8/2020,
+  and loads their compiled CSS that was in use at that time.
 
-  Base template is ${SITE_PACKAGES}/docutils/writers/html5_polyglot/template.txt
+  (Styling seems to change more often than basic page structure,
+  so to update, it may be sufficient to copy in the current
+  <link rel="stylesheet" ...> tags from any live package page.)
+
+  This extends the docutils base template found at
+  ${SITE_PACKAGES}/docutils/writers/html5_polyglot/template.txt
 -->
 
 <base href="https://pypi.org/">
 %(head)s
 <!-- template (stylesheet) omitted -->
 
-<link rel="stylesheet" href="/static/css/warehouse.a1809af1.css">
-<link rel="stylesheet" href="/static/css/fontawesome.4b73fd92.css">
-<link rel="stylesheet" href="/static/css/regular.19624371.css">
-<link rel="stylesheet" href="/static/css/solid.f478cfb1.css">
-<link rel="stylesheet" href="/static/css/brands.1ea560bf.css">
+<link rel="stylesheet" href="/static/css/warehouse-ltr.f2d4f304.css">
+<link rel="stylesheet" href="/static/css/fontawesome.6002a161.css">
+<link rel="stylesheet" href="/static/css/regular.98fbf39a.css">
+<link rel="stylesheet" href="/static/css/solid.c3b5f0b5.css">
+<link rel="stylesheet" href="/static/css/brands.2c303be1.css">
 <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,400italic,600,600italic,700,700italic|Source+Code+Pro:500">
 <link rel="icon" href="/static/images/favicon.6a76275d.ico" type="image/x-icon">
 
@@ -22,16 +27,16 @@
 
 <main id="#content">
 
-  <section class="banner">
+  <div class="banner">
     <div class="package-header">
     <div class="package-header__left">
       %(body_pre_docinfo)s
       %(docinfo)s
     </div>
     </div>
-  </section>
+  </div>
 
-  <section>
+  <div>
     <div class="tabs-container">
     <div class="vertical-tabs">
     <div class="vertical-tabs__panel">
@@ -45,7 +50,7 @@
     </div>
     </div>
     </div>
-  </section>
+  </div>
 
 </main>
 %(body_suffix)s

docs/_static/anymail-theme.css

@@ -1,31 +1,9 @@
 /* Anymail modifications to sphinx-rtd-theme styles */
 
-/* List item spacing: https://github.com/rtfd/sphinx_rtd_theme/issues/590 */
-/*        Regression: https://github.com/rtfd/sphinx_rtd_theme/issues/705 */
-.rst-content .section ol li p:last-child,
-.rst-content .section ul li p:last-child {
-  margin-bottom: 24px;
-}
-
-
-/* Pygments shell/console prompt: */
-.highlight .gp {
-  /* The RTD theme shows prompts the same color as other code.
-     We want to distinguish them (like most Pygments themes do). */
-  color: #d14;
-
-  /* Exclude prompt characters when copying from highlighted code. */
-  user-select: none;
-  -moz-user-select: none;
-  -webkit-user-select: none;
-  -ms-user-select: none;
-}
-
 
 /* Sticky table first column (used for ESP feature matrix) */
 table.sticky-left td:first-of-type,
 table.sticky-left th:first-of-type {
-  position: -webkit-sticky; /* Safari */
   position: sticky;
   left: 0;
   background-color: #fcfcfc; /* override transparent from .wy-table td */
@@ -36,7 +14,6 @@ table.sticky-left th:first-of-type[colspan] > p {
      since those always wrap a rubric <p> (in the specific table that uses this),
      just make the <p> sticky within the <td>. */
   display: inline-block;
-  position: -webkit-sticky; /* Safari */
   position: sticky;
   left: 17px; /* (.wy-table $table-padding-size) + (docutils border="1" in html) */
 }
@@ -57,12 +34,12 @@ table.sticky-left th:first-of-type[colspan] > p {
             https://github.com/rtfd/sphinx_rtd_theme/issues/92
 */
 .rst-content a code.xref {
-  color: #2980B9;
-  font-weight: inherit;
+  color: inherit;
+  /*font-weight: inherit;*/
 }
 .rst-content a:hover code.xref {
-  color: #3091d1;
+  color: inherit;
 }
 .rst-content a:visited code.xref {
-  color: #9B59B6;
+  color: inherit;
 }

docs/_static/version-alert.js

@@ -27,4 +27,8 @@ function warnOnLatestVersion() {
   parent.insertBefore(warning, parent.firstChild);
 }
 
-document.addEventListener('DOMContentLoaded', warnOnLatestVersion);
+if (document.readyState === 'loading') {
+  document.addEventListener('DOMContentLoaded', warnOnLatestVersion);
+} else {
+  warnOnLatestVersion();
+}

docs/conf.py

@@ -11,20 +11,25 @@
 
 import os
 import sys
-on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+from pathlib import Path
+
+ON_READTHEDOCS = os.environ.get('READTHEDOCS', None) == 'True'
+DOCS_PATH = Path(__file__).parent
+PROJECT_ROOT_PATH = DOCS_PATH.parent
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.insert(0, os.path.abspath('..'))
+sys.path.insert(0, PROJECT_ROOT_PATH.resolve())
 
 # define __version__ and __minor_version__ from ../anymail/_version.py,
 # but without importing from anymail (which would make docs dependent on Django, etc.)
 __version__ = "UNSET"
 __minor_version__ = "UNSET"
-with open("../anymail/_version.py") as f:
-    code = compile(f.read(), "../anymail/_version.py", 'exec')
-    exec(code)
+version_path = PROJECT_ROOT_PATH / "anymail/_version.py"
+code = compile(version_path.read_text(), version_path, 'exec')
+exec(code)
+
 
 # -- General configuration -----------------------------------------------------
 
@@ -50,7 +55,7 @@ master_doc = 'index'
 # General information about the project.
 project = 'Anymail'
 # noinspection PyShadowingBuiltins
-copyright = 'Anymail contributors (see AUTHORS.txt)'
+copyright = 'Anymail contributors'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -100,11 +105,11 @@ pygments_style = 'sphinx'
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-if not on_rtd:  # only import and set the theme if we're building docs locally
+if not ON_READTHEDOCS:  # only import and set the theme if we're building docs locally
     import sphinx_rtd_theme  # this seems to come with sphinx; if not, pip install it
     html_theme = 'sphinx_rtd_theme'
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
-# if on_rtd, readthedocs.org uses their theme by default (and specifying it here breaks them)
+# else readthedocs.org uses their theme by default (and specifying it here breaks them)
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -202,7 +207,7 @@ latex_elements = {
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
   ('index', 'Anymail.tex', 'Anymail Documentation',
-   'Anymail contributors (see AUTHORS.txt)', 'manual'),
+   'Anymail contributors', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -232,7 +237,7 @@ latex_documents = [
 # (source start file, name, description, authors, manual section).
 man_pages = [
     ('index', 'anymail', 'Anymail Documentation',
-     ['Anymail contributors (see AUTHORS.txt)'], 1)
+     ['Anymail contributors'], 1)
 ]
 
 # If true, show URL addresses after external links.
@@ -246,7 +251,7 @@ man_pages = [
 #  dir menu entry, description, category)
 texinfo_documents = [
   ('index', 'Anymail', 'Anymail Documentation',
-   'Anymail contributors (see AUTHORS.txt)', 'Anymail', 'Multi-ESP transactional email for Django.',
+   'Anymail contributors', 'Anymail', 'Multi-ESP transactional email for Django.',
    'Miscellaneous'),
 ]
 
@@ -275,10 +280,13 @@ intersphinx_mapping = {
 
 
 def setup(app):
-    app.add_stylesheet("anymail-theme.css")
-    app.add_javascript("anymail-config.js")
-    app.add_javascript("version-alert.js")
-    app.add_javascript("https://unpkg.com/rate-the-docs")
+    app.add_css_file("anymail-theme.css")
+    # Inline <script> for anymail-config.js to avoid non-async JS load:
+    # app.add_js_file("anymail-config.js")
+    anymail_config_js = (DOCS_PATH / "_static/anymail-config.js").read_text()
+    app.add_js_file(None, body=anymail_config_js)
+    app.add_js_file("version-alert.js", **{"async": "async"})
+    app.add_js_file("https://unpkg.com/rate-the-docs", **{"async": "async"})
 
     # Django-specific roles, from https://github.com/django/django/blob/master/docs/_ext/djangodocs.py:
     app.add_crossref_type(

docs/esps/amazon_ses.rst

@@ -13,8 +13,6 @@ AWS SDK for Python, and includes sending, tracking, and inbound receiving capabi
     Depending on your needs, one of them may be more appropriate than Anymail.
 
 
-.. versionadded:: 2.1
-
 .. _Amazon Simple Email Service: https://aws.amazon.com/ses/
 .. _Boto 3: https://boto3.readthedocs.io/en/stable/
 

docs/esps/mailgun.rst

@@ -137,13 +137,6 @@ use Anymail's :attr:`~anymail.message.AnymailMessage.envelope_sender`
         message.envelope_sender = "anything@mail2.example.com"  # the "anything@" is ignored
 
 
-.. versionchanged:: 2.0
-
-    Earlier Anymail versions looked for a special `sender_domain` key in the message's
-    :attr:`~anymail.message.AnymailMessage.esp_extra` to override Mailgun's sender domain.
-    This is still supported, but may be deprecated in a future release. Using
-    :attr:`~anymail.message.AnymailMessage.envelope_sender` as shown above is now preferred.
-
 .. _Mailgun sender domain:
     https://help.mailgun.com/hc/en-us/articles/202256730-How-do-I-pick-a-domain-name-for-my-Mailgun-account-
 

docs/esps/mailjet.rst

@@ -5,8 +5,6 @@ Mailjet
 
 Anymail integrates with the `Mailjet`_ email service, using their transactional `Send API`_ (v3).
 
-.. versionadded:: 0.11
-
 .. _mailjet-v31-api:
 
 .. note::

docs/esps/mandrill.rst

@@ -257,14 +257,6 @@ for each event in the batch.)
     https://mandrill.zendesk.com/hc/en-us/articles/205583197-Inbound-Email-Processing-Overview
 
 
-.. versionchanged:: 1.3
-    Earlier Anymail releases used :samp:`.../anymail/mandrill/{tracking}/` as the tracking
-    webhook url. With the addition of inbound handling, Anymail has dropped "tracking"
-    from the recommended url for new installations. But the older url is still
-    supported. Existing installations can continue to use it---and can even install it
-    on a Mandrill *inbound* route to avoid issuing a new webhook key.
-
-
 .. _migrating-from-djrill:
 
 Migrating from Djrill
@@ -380,8 +372,6 @@ Changes to EmailMessage attributes
   instead. You'll need to pass a valid email address (not just a domain),
   but Anymail will use only the domain, and will ignore anything before the @.
 
-  .. versionchanged:: 2.0
-
 **Other Mandrill-specific attributes**
   Djrill allowed nearly all Mandrill API parameters to be set
   as attributes directly on an EmailMessage. With Anymail, you

docs/inbound.rst

@@ -3,8 +3,6 @@
 Receiving mail
 ==============
 
-.. versionadded:: 1.3
-
 For ESPs that support receiving inbound email, Anymail offers normalized handling
 of inbound events.
 
@@ -168,7 +166,7 @@ Normalized inbound message
         :class:`~anymail.utils.EmailAddress` object, which makes it easier to access
         the parsed address fields:
 
-        .. code-block:: python
+        .. code-block:: pycon
 
             >>> str(message.from_email)  # the fully-formatted address
             '"Dr. Justin Customer, CPA" <jcustomer@example.com>'
@@ -367,11 +365,6 @@ have these methods:
         The errors param is as in :meth:`~bytes.decode`. The default "replace" substitutes the
         Unicode "replacement character" for any illegal characters in the text.
 
-        .. versionchanged:: 2.1
-
-            Changed to use attachment's declared charset by default,
-            and added errors option defaulting to replace.
-
     .. method:: get_content_bytes()
 
         Returns the raw content of the attachment as bytes. (This will automatically decode

docs/installation.rst

@@ -282,20 +282,11 @@ This is actually implemented using HTTP basic authentication, and the string is
 technically a "username:password" format. But you should *not* use any real
 username or password for this shared secret.
 
-.. versionchanged:: 1.4
-
-    The earlier WEBHOOK_AUTHORIZATION setting was renamed WEBHOOK_SECRET, so that
-    Django error reporting sanitizes it. Support for the old name was dropped in
-    Anymail 2.0, and if you have not yet updated your settings.py, all webhook calls
-    will fail with a "missing or invalid basic auth" error.
-
 
 .. setting:: ANYMAIL_REQUESTS_TIMEOUT
 
 .. rubric:: REQUESTS_TIMEOUT
 
-.. versionadded:: 1.3
-
 For Requests-based Anymail backends, the timeout value used for all API calls to your ESP.
 The default is 30 seconds. You can set to a single float, a 2-tuple of floats for
 separate connection and read timeouts, or `None` to disable timeouts (not recommended).

docs/requirements.txt

@@ -0,0 +1,4 @@
+# (Pygments defaulted "python" to Python 2 before v2.5.0; it doesn't use semver)
+Pygments~=2.6.1
+sphinx~=3.1
+sphinx-rtd-theme~=0.5.0

docs/sending/anymail_additions.rst

@@ -76,8 +76,6 @@ an :ref:`unsupported feature <unsupported-features>` error.
 
     .. attribute:: envelope_sender
 
-        .. versionadded:: 2.0
-
         Set this to a `str` email address that should be used as the message's
         envelope sender. If supported by your ESP, this will become the Return-Path
         in the recipient's mailbox.

docs/sending/django_email.rst

@@ -145,10 +145,6 @@ has special handling for certain headers. Anymail replicates its behavior for co
   :class:`to <django.core.mail.EmailMessage>` list. Spoofing the :mailheader:`To` header like this
   is popular with spammers, and almost none of Anymail's supported ESPs allow it.
 
-.. versionchanged:: 2.0
-
-    Improved header-handling compatibility with Django's SMTP EmailBackend.
-
 
 .. _unsupported-features:
 

docs/sending/exceptions.rst

@@ -43,8 +43,6 @@ Exceptions
 
 .. exception:: AnymailInvalidAddress
 
-    .. versionadded:: 0.7
-
     The send call will raise a :exc:`!AnymailInvalidAddress` error if you
     attempt to send a message with invalidly-formatted email addresses in
     the :attr:`from_email` or recipient lists.