Documentation Remove unneeded closing tags in TOC

[penguinolog]

Generated construction before change:

</a></p><h3>Table of contents</a></h3>

Checklist

• I've ensured that similar functionality has not already been implemented
• I've ensured that similar functionality has not earlier been proposed and declined
• I've branched off the master or python-dual-support branch
• I've merged fresh upstream into my branch recently
• I've ran tox successfully in local environment
• I've included docstrings and/or documentation and/or examples for my code (if this is a new feature)

[wardi]

I'd bet there was an <a name=...> around the title at some point