Shift Projects to Documentation. (#90)

Author: kattni

src/beeware_docs_tools/overrides/partials/header.html

@@ -15,7 +15,7 @@
         <a class="nav-link" href="https://beeware.org/about">About</a>
       </li>
       <li class="nav-item active">
-        <a class="nav-link" href="https://beeware.org/project">Projects</a>
+        <a class="nav-link" href="https://beeware.org/docs">Documentation</a>
       </li>
       <li class="nav-item">
         <a class="nav-link" href="https://beeware.org/community">Community</a>