gh-150693: Combine docs sections for external resources (#150694)

Author: miameows

Doc/tools/templates/indexcontent.html

@@ -82,10 +82,16 @@ <h1>{{ docstitle|e }}</h1>
   <p><strong>{% trans %}Other resources:{% endtrans %}</strong></p>
   <div class="contentstable">
     <ul>
+      <li class="biglink"><a class="biglink" href="https://devguide.python.org">{% trans %}Python developer's guide{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Information on contributing to Python{% endtrans %}</span></li>
       <li class="biglink"><a class="biglink" href="https://packaging.python.org">{% trans %}Python Packaging User Guide{% endtrans %}</a><br>
          <span class="linkdescr">{% trans %}Resources relating to Python packaging{% endtrans %}</span></li>
+      <li class="biglink"><a class="biglink" href="https://www.python.org/doc/av/">{% trans %}Audio/visual talks{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Podcasts, talks, and video presentations from the community{% endtrans %}</span></li>
     </ul>
     <ul>
+      <li class="biglink"><a class="biglink" href="https://peps.python.org/">{% trans %}Python Enhancement Proposals{% endtrans %}</a><br>
+         <span class="linkdescr">{% trans %}Index of proposed improvements to Python{% endtrans %}</span></li>
       <li class="biglink"><a class="biglink" href="https://typing.python.org">{% trans %}Static Typing with Python{% endtrans %}</a><br>
          <span class="linkdescr">{% trans %}Information and guides about Python type safety{% endtrans %}</span></li>
     </ul>

Doc/tools/templates/indexsidebar.html

@@ -6,12 +6,3 @@ <h3>{% trans %}Docs by version{% endtrans %}</h3>
   {% include "_docs_by_version.html" without context %}
   <li><a href="https://www.python.org/doc/versions/">{% trans %}All versions{% endtrans %}</a></li>
 </ul>
-<h3>{% trans %}Other resources{% endtrans %}</h3>
-<ul>
-  {# XXX: many of these should probably be merged in the main docs #}
-  <li><a href="https://peps.python.org/">{% trans %}PEP index{% endtrans %}</a></li>
-  <li><a href="https://wiki.python.org/moin/BeginnersGuide">{% trans %}Beginner's guide{% endtrans %}</a></li>
-  <li><a href="https://wiki.python.org/moin/PythonBooks">{% trans %}Book list{% endtrans %}</a></li>
-  <li><a href="https://www.python.org/doc/av/">{% trans %}Audio/visual talks{% endtrans %}</a></li>
-  <li><a href="https://devguide.python.org/">{% trans %}Python developer’s guide{% endtrans %}</a></li>
-</ul>