Add information about hermeticity and how to troubleshoot non-hermetic builds
<li><a href="/versions/{{ current_version }}/configurable-attributes.html">Configurable Attributes</a></li>
<li><a href="/versions/{{ current_version }}/platforms-intro.html">Platforms and Toolchains</a></li>
<li><a href="/versions/{{ current_version }}/visibility.html">Visibility</a></li>
+ <li><a href="/versions/{{ current_version }}/hermeticity.html">Hermeticity</a></li>
</ul>
<h3>Releases</h3>
