The support page is the go-to page for the "how to get help" question,
which previously was hidden inside the TPA-RFC-2 standard.

This basically copies that part of the TPA-RFC-2 policy, but could
eventually diverge without needing to update the policy, for informal
stuff.

I started working on this page while trying to address
#40382 ("document the triage process"), but I'm not
actually sure triage documentation should go there, as this page feels
more targeted at users, and only users.

howto/incident-response.md would seem like a better space for this.

Also, this is a toplevel page because it's more important than
everything else, so it warrants its own special space.

The instructions were saying to sync them, but they were actually out
of sync already.

This was already in the home page, but not prominent. Makes sense to
have it in the main sidebar, and since those are in sync...

This breaks the automatic generation, but it's unlikely anyone would
have noticed that anyways.

It would be better if those sections were represented in the folder
hierarchy as well, but that involves moving a lot of pages around,
which would break too many links.

Ideally, the GitLab wiki would support redirects, but unfortunately it
didn't seem to, in my tests:

https://forum.gitlab.com/t/gitlab-wiki-redirections-and-other-gollum-features/42993/1

The wiki still claimed it has its source at https://gitweb.torproject.org/project/help/wiki.  Correct that

This is:

    ikiwiki2hugo.py --exclude .pytest_cache

With the latest script from:

<https://gitlab.com/anarcat/scripts/-/blob/master/ikiwiki2hugo.py>

... as of right now.

This is a test to see if it's worth doing by hand.

We also rephrase some things and fix a broken link (git) while we're here.

fix title to match original when relevant