[VOL-2875] Documentation update

- Updated the main landing page and overview documentation
- Added the lab setup (copied from CORD docs)
- Use forked sphinx-multiversion to publish docs, which allows versions
  to be listed at bottom of sidebar
- Updated logo and favicon, fixed CSS to make logo legible
- Use VERSION file to set the version in the sidebar
- Add more words to dictionary
- removed reload functionality that is nonworking in Sphinx 2.x
- Fixed lint/linkcheck issues

Change-Id: I032e67d76393778fc697944a6d5df9c8cdacbbc4
diff --git a/_templates/meta_refresh.html b/_templates/meta_refresh.html
new file mode 100644
index 0000000..b940c76
--- /dev/null
+++ b/_templates/meta_refresh.html
@@ -0,0 +1,8 @@
+<!--
+SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+SPDX-License-Identifier: Apache-2.0
+--!>
+<html><head>
+    <meta charset="UTF-8">
+    <meta http-equiv="refresh" content="0;url=master/index.html" />
+</head></html>
diff --git a/_templates/versions.html b/_templates/versions.html
new file mode 100644
index 0000000..8ed5e31
--- /dev/null
+++ b/_templates/versions.html
@@ -0,0 +1,31 @@
+<!--
+SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+SPDX-License-Identifier: Apache-2.0
+--!>
+{%- if current_version %}
+<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"> Other Versions</span>
+    v: {{ current_version.name }}
+    <span class="fa fa-caret-down"></span>
+  </span>
+  <div class="rst-other-versions">
+    {%- if versions.tags %}
+    <dl>
+      <dt>Tags</dt>
+      {%- for item in versions.tags %}
+      <dd><a href="{{ item.url }}">{{ item.name }}</a></dd>
+      {%- endfor %}
+    </dl>
+    {%- endif %}
+    {%- if versions.branches %}
+    <dl>
+      <dt>Branches</dt>
+      {%- for item in versions.branches %}
+      <dd><a href="{{ item.url }}">{{ item.name }}</a></dd>
+      {%- endfor %}
+    </dl>
+    {%- endif %}
+  </div>
+</div>
+{%- endif %}