doc: cleanup css, search, version choices

Update CSS customization to improve read-the-docs theme for our use.
Improved search results (removing most reST markup), improve display of
doc version choices.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/_templates/breadcrumbs.html

@@ -1,22 +0,0 @@
-{% extends "!breadcrumbs.html" %}
-{% block breadcrumbs_aside %}
-
-<li class="wy-breadcrumbs-aside">
-   <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"> Project ACRN</span>
-         version: {{ current_version }}
-         <span class="fa fa-caret-down"></span>
-      </span>
-      <div class="rst-other-versions">
-         <dl>
-            <dt>Versions</dt>
-               {% for slug, url in versions %}
-               <dd><a href="{{ url }}">{{ slug }}</a></dd>
-              {% endfor %}
-         </dl>
-      </div>
-   </div>
-</li>
-{# {{ super() }} #}
-{% endblock %}

doc/_templates/versions.html

@@ -0,0 +1,25 @@
+{# Add rst-badge after rst-versions for small badge style. #}
+  <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"> Project ACRN</span>
+      v: {{ current_version }}
+      <span class="fa fa-caret-down"></span>
+    </span>
+    <div class="rst-other-versions">
+      <dl>
+        <dt>{{ _('Versions') }}</dt>
+        {% for slug, url in versions %}
+          <dd><a href="{{ url }}">{{ slug }}</a></dd>
+        {% endfor %}
+      </dl>
+      <dl>
+        <dt>{{ _('On projectacrn.org') }}</dt>
+          <dd>
+            <a href="https://www.projectacrn.org/">Project Home</a>
+          </dd>
+          <dd>
+            <a href="https://github.com/projectacrn/acrn-hypervisor/wiki">Wiki</a>
+          </dd>
+      </dl>
+    </div>
+  </div>