DOC: point governance link at built docs rather than git repo

Author: tacaswell

docs/_templates/landing_footer.html

@@ -47,7 +47,7 @@ <h1>Matplotlib</h1>
       </li>
       <li><a href="https://matplotlib.org/stable/users/project/license.html">License</a></li>
       <li>
-        <a href="https://github.com/matplotlib/governance">Governance</a>
+        <a href="https://matplotlib.org/governance/">Governance</a>
       </li>
       <li><a href="https://numfocus.org/sponsored-projects">NumFOCUS Fiscally Sponsored Project</a></li>
     </ul>