The wiki is open for anyone to modify. If you do make changes, please do explain what you did and possibly why. This will make it easier for other folks (esp. repo followers) to see what's going on. This information is also available at page history and works as an archival tool that way.
If you happen to have some ideas (wiki restructuring etc.), feel free to use the issue tracker for that. The wiki is still in fairly rough shape but some parts are quite useful already.
You are free to add new pages for new library categories and whatnot. It's better to do something than ask permission for it so go ahead if you want to!
I guess that's about it. Keep in mind that it's you who keep this thing running. Any contributions, no matter how small, are appreciated. :)