emacs/mps/manual/source/_templates/layout.html

{# manual/source/_templates/layout.html -- add index to manual sidebar.
 #
 # See https://stackoverflow.com/a/37843854 .
 #}

{% extends "!layout.html" %}

  {% block menu %}
    {{ super() }}

<p class="caption" role="heading">
  <span class="caption-text">Indices and tables</span>
</p>

<ul>

  {# The class toctree-l1 seems to correspond to list items generated
     by a Sphinx toctree directive that are at depth 1.  I have not
     found documented confirmation of this but it is confirmed
     `_toctree_add_classes
     <https://github.com/sphinx-doc/sphinx/blob/bb74aec2b6aa1179868d83134013450c9ff9d4d6/sphinx/environment/adapters/toctree.py#L403-L430>`_
     in the Sphinx source code.  If the list layout goes wonky, this
     might be to blame.  RB 2023-10-20. #}

  <li class="toctree-l1">

    <a class="reference internal" href="{{pathto('genindex.html', 1)}}">Index</a>

    {# Module index and search page aren't used in the MPS manual but
       might be in future.  This is how they might be added. #}

    {# <a class="reference internal" href="{{pathto('modindex.html', 1)}}">Module Index</a> #}

    {# <a class="reference internal" href="{{pathto('search.html', 1)}}">Search Page</a> #}

  </li>

</ul>

  {% endblock %}