Add template blocks for an RTD-like version switcher

docs/_static/releases.css

@@ -0,0 +1 @@
+.rst-other-versions .current-release { font-weight: 700; }

docs/_templates/layout.html

@@ -0,0 +1,35 @@
+{% extends "!layout.html" %}
+
+{% block extrahead %}
+<link rel="stylesheet" href="_static/releases.css" type="text/css" />
+{% endblock %}
+
+{% block extrabody %}
+<div class="rst-versions" data-toggle="rst-versions" role="note" aria-label="versions">
+    <span class="rst-current-version" data-toggle="rst-current-version">
+        <span class="fa fa-book">SecureDrop Docs</span>
+        v: {{ release }}
+        <span class="fa fa-caret-down"></span>
+    </span>
+    <div class="rst-other-versions">
+        <dl>
+            <dt>Versions</dt>
+            <dd{% if release == "stable" %} class="current-release"{% endif %}>
+                <a href="/en/stable/{{ pagename }}.html">stable</a>
+            </dd>
+            <dd{% if release == "latest" %} class="current-release"{% endif %}>
+                <a href="/en/latest/{{ pagename }}.html">latest</a>
+            </dd>
+        </dl>
+        <dl>
+            <dt>Downloads</dt>
+            <dd><a href="/en/{{ release }}/SecureDrop.pdf">PDF</a></dd>
+        </dl>
+        <hr>
+        <small>
+            A project of <a href="https://freedom.press/">Freedom of the Press Foundation</a> ·
+            <a href="https://freedom.press/privacy-policy/">Privacy Policy</a>
+        </small>
+    </div>
+</div>
+{% endblock %}

docs/conf.py

@@ -148,7 +148,7 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-# html_static_path = ['_static']
+html_static_path = ['_static']
 
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied