Update template for newest Sphinx.

Doc/conf.py

@@ -74,9 +74,6 @@ html_last_updated_fmt = '%b %d, %Y'
 # typographically correct entities.
 html_use_smartypants = True
 
-# Content template for the index page, filename relative to this file.
-html_index = 'indexcontent.html'
-
 # Custom sidebar templates, filenames relative to this file.
 html_sidebars = {
     'index': 'indexsidebar.html',
@@ -85,6 +82,7 @@ html_sidebars = {
 # Additional templates that should be rendered to pages.
 html_additional_pages = {
     'download': 'download.html',
+    'index': 'indexcontent.html',
 }
 
 # Output file base name for HTML help builder.

Doc/tools/sphinxext/indexcontent.html

@@ -1,3 +1,5 @@
+{% extends "defindex.html" %}
+{% block tables %}
   <p><strong>Parts of the documentation:</strong></p>
   <table class="contentstable" align="center"><tr>
     <td width="50%">
@@ -54,3 +56,4 @@
       <p class="biglink"><a class="biglink" href="{{ pathto("copyright") }}">Copyright</a></p>
     </td></tr>
   </table>
+{% endblock %}