We actually primarily use StackOverflow for this (as it's the first resource many devs go to, as you did, and it's collaborative). We even pre-seed questions an

We actually primarily use StackOverflow for this (as it's the first resource many devs go to, as you did, and it's collaborative). We even pre-seed questions and answers for releases, sometimes. If you find an answer on SO is out of date - suggest a new answer (or ask for one) and get it updated (there's far, far too many for us to keep explicit track of them, there's only a handful of us on the team)! :D