I was meant to comment on this a while back... but I think I had issues... anyway I would just like to say... why not just use a ready to go tool such as TikiWiki ? heres an example of mine... I will practically be doing this nevertheless
http://www.tmsubs.co.uk
In case the question gets raised... yes its the exact same engine used by Wikipedia. albeit the base engine.
I am going to post a public project thread in Geek Culture soon... keep peeled!. if you fancy this engine hosted for free... You will probably want to see that thread.
I might have been confused is this to replace the inbuilt TGC help documents? if so then ignore the above

I am intent on an online reference site... mostly because I use dual screens so I prefer not using the built in help documentation so I wanted an online system so I made my dev wiki

anyway this is all cache 22 I am having one of those days today..