fixed links on /modules/ and module specific pages

Hopefully you'll agree with the changes I've made here.

I noticed all of the "git main" links were broken, the "obsolete" ones too.

And then when you went through to module specific links the links all went to the old repos that are now archived.

So I've updated those too.

If the repo was obsolete and didnt exist on gitlab any more, I also now deal with that too.