C as in what's a wiki? If so, a wiki is a site which is collectively written by whoever visits and decides to click the "edit" button on the page they are viewing. So pretty much, you write something, someone else edits it and adds to it, someone else edits that, someone else edits that, etc and eventually you have some really informative pages, and all the edit information, such as who did it as well as a mirror of all the previous "versions" gets saved so you can see the progress of it.
Generally everything on a wiki is licensed under some sort of "Open Source" license, such as Creative Commons or GNU Free Document License, so everything on them can be redistributed freely.
Thanks a lot for the generous offer of pictures
, but I'd like to see you edit the wiki even more. If you're worried about it being difficult, it isn't at all. You don't have to know any HTML or anything.