Further additions to the theme

docs/source/_templates/sourcelink.html

@@ -0,0 +1,13 @@
+{#
+Page source link
+
+#}
+{%- if show_source and has_source and sourcename %}
+  <div role="note" aria-label="source link">
+    <!--h3>{{ _('This Page') }}</h3-->
+    <ul class="this-page-menu">
+      <li><a href="{{ pathto('_sources/' + sourcename, true)|e }}"
+            rel="nofollow">{{ _('Show Page Source') }}</a></li>
+    </ul>
+   </div>
+{%- endif %}