docs/_themes/sphinx_rtd_theme/footer.html

<footer>
  {% if (theme_prev_next_buttons_location == 'bottom' or theme_prev_next_buttons_location == 'both') and (next or prev) %}
    <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
      {% if next %}
        <a href="{{ next.link|e }}" class="btn btn-neutral float-right" title="{{ next.title|striptags|e }}" accesskey="n" rel="next">{{ _('Next') }} <span class="fa fa-arrow-circle-right"></span></a>
      {% endif %}
      {% if prev %}
        <a href="{{ prev.link|e }}" class="btn btn-neutral float-left" title="{{ prev.title|striptags|e }}" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> {{ _('Previous') }}</a>
      {% endif %}
    </div>
  {% endif %}

  <hr/>

  <div role="contentinfo">
    <p>
    {%- if show_copyright %}
      {%- if hasdoc('copyright') %}
        {% set path = pathto('copyright') %}
        {% set copyright = copyright|e %}
        &copy; <a href="{{ path }}">{% trans %}Copyright{% endtrans %}</a> {{ copyright }}
      {%- else %}
        {% set copyright = copyright|e %}
        &copy; {% trans %}Copyright{% endtrans %} {{ copyright }}
      {%- endif %}
    {%- endif %}

       &bull; <a href="/docs/contact.html">Contact</a>

    {%- if build_id and build_url %}
      <span class="build">
        {# Translators: Build is a noun, not a verb #}
        {% trans %}Build{% endtrans %}
        <a href="{{ build_url }}">{{ build_id }}</a>.
      </span>
    {%- elif commit %}
      <span class="commit">
        {# Translators: the phrase "revision" comes from Git, referring to a commit #}
        {% trans %}Revision{% endtrans %} <code>{{ commit }}</code>.
      </span>
    {%- endif %}
    {%- if last_updated %}
      <span class="lastupdated">
        {% trans last_updated=last_updated|e %}Last updated on {{ last_updated }}.{% endtrans %}
      </span>
    {%- endif %}

    </p>
  </div>

  {%- if show_sphinx %}
    {% set sphinx_web = '<a href="https://www.sphinx-doc.org/">Sphinx</a>' %}
    {% set readthedocs_web = '<a href="https://readthedocs.org">Read the Docs</a>'  %}
    {# Translators: the variable "sphinx_web" is a link to the Sphinx project documentation with the text "Sphinx" #}
    {% trans sphinx_web=sphinx_web, readthedocs_web=readthedocs_web %}Built with {{ sphinx_web }} using a{% endtrans %}
    {# Translators: "theme" refers to a theme for Sphinx, which alters the appearance of the generated documenation #}
    <a href="https://github.com/readthedocs/sphinx_rtd_theme">{% trans %}theme{% endtrans %}</a>
    {# Translators: this is always used as "provided by Read the Docs", and should not imply Read the Docs is an author of the generated documentation. #}
    {% trans %}provided by {{ readthedocs_web }}{% endtrans %}.
  {%- endif %}

  {%- block extrafooter %} {% endblock %}

</footer>