How about a wiki-style website ? (with a forum of course!). I don't have enough time to contribute to a full website project, but I'm sure lot of people could easily cooperate on little sections of a wiki-style website (putting correct tutorials, tips etc...)
Having used a wiki with Ren'Py and abandoned it, it's usually a bad idea. If you can't find people to contribute now, you're unlikely to find people to contribute to the wiki. At the same time, wikis wind up having a large ongoing cost when it comes to account approval, spam protection, etc.Â