DOC Remove hardcoded table of contents

[GuySartorelli]

The new docs site will be generating a table of contents that is more accurate and works on all pages, so we need to remove the redundant hardcoded ToC.

I thought I remembered the graphql docs having them too, but it turns out those are children lists, which won't be replaced with the automated ToC.

Note I haven't bothered wrapping the commits list for these nor for CMS 3, since they're so old now I doubt they'll be looked at very much.

Issue

• Upgrade to node 24 doc.silverstripe.org#347