Do mean some kind of hierarchical menu? Because it can be done using a special tag, as was done for example for the GSoC blog last year.
If there's enough interest in it I guess we could have a main community wiki post that would link to other wiki pages. And we could pin this main wiki post so that's it's always easily accessible. I think that would make sense because there's indeed quite a bit of content on the forum that's not part of the official doc, but that can be very useful anyway.