proxmox-backup/docs/_templates/index-sidebar.html

<h3>Navigation</h3>
{{ toctree(includehidden=theme_sidebar_includehidden, collapse=True, titles_only=True) }}
{% if theme_extra_nav_links %}
<hr />
<h3>Links</h3>
<ul>
    {% for text, uri in theme_extra_nav_links.items() %}
    <li class="toctree-l1"><a href="{{ uri }}">{{ text }}</a></li>
    {% endfor %}
</ul>
{% endif %}