I think a wiki is a good idea. My anti-virus warns me about slimwiki.com if thats where you are hosting it. But could be false positive.
Try take a look at https://meta.miraheze.org Its is also free and its run by open-source and donations, but without the same limitations you have on slimwiki (1 admin, 1GB etc). I made a wiki there, and I was quite satisfied with it.