Redirect old "HelpHub" content to their new forever-home

[Clorith]

Many moons ago, back when HelpHub and extensive user-oriented documentation was just a starry dream, work begun on cataloging, and creating the content that should go into it.

For this, with limited resources, the make/support site was used to both coordinate, and write/collaborate on content.

Fast forward over a decade, and we now have a proper home for this type of documentation, and it is a much better home than a make teams "little corner", where the original content unfortunately never got forwarded initially.

To be able to remove the content from make/support, we should get proper redirects in place, this is content that in some cases shows up as top results in searches, so we don't want to leave users at a dead end.

I've created an overview of all the make/support links, and corresponding links they should be redirected to at ​https://docs.google.com/spreadsheets/d/1z4WJ859wKYssKIqmCxjHWFj_Kg_KGXO5R8vuxnchH7U

There is currently only one entry that is unknown, there is a tracking ticket with the docs team on what to do about this content, but it shouldn't be a blocker to get everything else redirected accordingly I don't think? (unless it's preferable to get it all done in one go, of course)