Merge pull request matplotlib#13867 from dstansby/doccontents

DOC: Rename "docs" to "contents" in navigation bar

Author: tacaswell

doc/_templates/layout.html

@@ -41,7 +41,7 @@ <h3>{{ _('Navigation') }}</h3>
         <li><a href="{{ pathto('gallery/index') }}">examples</a>|&nbsp;</li>
         <li><a href="{{ pathto('tutorials/index') }}">tutorials</a>|&nbsp;</li>
         <li><a href="{{ pathto('api/api_overview') }}">API</a>|&nbsp;</li>
-        <li><a href="{{ pathto('contents') }}">docs</a> &raquo;</li>
+        <li><a href="{{ pathto('contents') }}">contents</a> &raquo;</li>
 
         {%- for parent in parents %}
           <li><a href="{{ parent.link|e }}" {% if loop.last %}{{