Remove Sphinx/Read-the-Docs plug on every doc page (#37023)

* Remove Sphinx/Read-the-Docs plug on every doc page

No need to have this on every page.

This fixes #37021

* Reinstated RTD credit with revised wording.

* Re-removed RTD footer boilerplate.

docs/docsite/_themes/sphinx_rtd_theme/footer.html

@@ -22,14 +22,9 @@
 </script>
 
   <p>
-  Copyright © 2018 Red Hat, Inc.
+  Copyright © 2018 Red Hat, Inc. <br/>
-  <br>
-
   {%- if last_updated %}
     {% trans last_updated=last_updated|e %}Last updated on {{ last_updated }}.{% endtrans %}
   {%- endif %}
   </p>
-<p>
-Ansible docs are generated from <a href="https://github.com/ansible/ansible">GitHub sources</a> using <a href="http://sphinx-doc.org/">Sphinx</a> using a theme provided by <a href="http://readthedocs.org">Read the Docs</a>.
-</p>
 </footer>