Docs: update readme test rendering to new PyPI layout, styles

docs/_readme/template.txt

@@ -0,0 +1,51 @@
+%(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).
+
+  Base template is ${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="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">
+
+%(body_prefix)s
+
+<main id="#content">
+
+  <section class="banner">
+    <div class="package-header">
+    <div class="package-header__left">
+      %(body_pre_docinfo)s
+      %(docinfo)s
+    </div>
+    </div>
+  </section>
+
+  <section>
+    <div class="tabs-container">
+    <div class="vertical-tabs">
+    <div class="vertical-tabs__panel">
+    <div id="description" class="vertical-tabs__content">
+    <h2 class="page-title">Project description</h2>
+
+    <div class="project-description">
+      %(body)s
+    </div>
+    </div>
+    </div>
+    </div>
+    </div>
+  </section>
+
+</main>
+%(body_suffix)s