[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/_static/css/rtd_theme_mods.css b/_static/css/rtd_theme_mods.css
index 30da586..be943dc 100644
--- a/_static/css/rtd_theme_mods.css
+++ b/_static/css/rtd_theme_mods.css
@@ -23,3 +23,13 @@
 .wy-table-responsive table td, .wy-table-responsive table th {
   white-space: normal;
 }
+
+.wy-side-nav-search {
+  background-color: #d9d9d9;
+}
+
+.wy-side-nav-search>div.version {
+  color: #404040;
+}
+
+