docs: Redirect to website, take 2
The initial attempt failed, as seen here: https://gnome.pages.gitlab.gnome.org/tracker/_redirects
The error was:
rule 1: error: no domain-level redirects to outside sites
To get around this, add a HTML page that redirects to the new website. Requests for /faq will now go to the main page, but it shouldn't be too hard to find the FAQ link from there.
Overview links are removed as we already hav https://gnome.pages.gitlab.gnome.org/tracker/overview.html (updated slightly in this MR)