My recommendation is to get rid of it. I put my docs in the repo with the code so we know who wrote it, when they wrote it, what version of the code was current when they wrote it and can easily back out changes if someone wrote something wrong.

I document everything in text, but have a tool that scans text and produces basic HTML with paragraphs and links to images.

That being said... maybe a tool that scans a collection of repos and indexes search terms would be really cool. Right now I can only search my current repo.

IMHO, I believe the problem with wikis is its easy to create a wiki page, but it's hard to figure out if you should remove a page. With the "docs in repo" approach, we're okay with removing docs since it's relatively easy to bring them back.