Add email templates for user notifications and account management

- Created a base email template (base.html) for consistent styling across all emails.
- Added moderation approval email template (moderation_approved.html) to notify users of approved submissions.
- Added moderation rejection email template (moderation_rejected.html) to inform users of required changes for their submissions.
- Created password reset email template (password_reset.html) for users requesting to reset their passwords.
- Developed a welcome email template (welcome.html) to greet new users and provide account details and tips for using ThrillWiki.

django/staticfiles/admin/js/collapse.js

@@ -0,0 +1,43 @@
+/*global gettext*/
+'use strict';
+{
+    window.addEventListener('load', function() {
+        // Add anchor tag for Show/Hide link
+        const fieldsets = document.querySelectorAll('fieldset.collapse');
+        for (const [i, elem] of fieldsets.entries()) {
+            // Don't hide if fields in this fieldset have errors
+            if (elem.querySelectorAll('div.errors, ul.errorlist').length === 0) {
+                elem.classList.add('collapsed');
+                const h2 = elem.querySelector('h2');
+                const link = document.createElement('a');
+                link.id = 'fieldsetcollapser' + i;
+                link.className = 'collapse-toggle';
+                link.href = '#';
+                link.textContent = gettext('Show');
+                h2.appendChild(document.createTextNode(' ('));
+                h2.appendChild(link);
+                h2.appendChild(document.createTextNode(')'));
+            }
+        }
+        // Add toggle to hide/show anchor tag
+        const toggleFunc = function(ev) {
+            if (ev.target.matches('.collapse-toggle')) {
+                ev.preventDefault();
+                ev.stopPropagation();
+                const fieldset = ev.target.closest('fieldset');
+                if (fieldset.classList.contains('collapsed')) {
+                    // Show
+                    ev.target.textContent = gettext('Hide');
+                    fieldset.classList.remove('collapsed');
+                } else {
+                    // Hide
+                    ev.target.textContent = gettext('Show');
+                    fieldset.classList.add('collapsed');
+                }
+            }
+        };
+        document.querySelectorAll('fieldset.module').forEach(function(el) {
+            el.addEventListener('click', toggleFunc);
+        });
+    });
+}