Table of content listing H4-s

[fcoveram]

In this page, the table of content component lists H4 headings. Not sure whether this was intentional or not, but it might be unnecessary to jump among sections and summarize the page content.

At the same time, the TOC doesn't keep fixed at the top and it misses the "back to top" action.

[adamwoodnz]

At the same time, the TOC doesn't keep fixed at the top and it misses the "back to top" action.

This is the behaviour when the ToC doesn't fit within the viewport.

Some fairly major changes to this are covered in #525, and I think this ToC will fit on a typical desktop screen after this. If the h4s are also removed it's even more likely.