Fixed "related documentation" headings by incorporating orphan pages into left nav and removing the heading from all relevant pages. Simultaneously reorganized content as required by[]
#set ($path = "/versions/{{ site.version }}/be")
#set ($bazelbuildGithub = "https://github.com/bazelbuild")
-<h3>Build Encyclopedia</h3>
+**Build Encyclopedia**
<ul class="sidebar-nav">
<li><a href="${path}/overview.html">Overview</a></li>
