Allow someone to edit documentation online.

I'm not sure how to enable this, but this would be the killer feature for DocumentJS. Ideally, a user's workflow might be:
1. Go to a page, see an "edit this" button. Click it.
2. Login to github.
3. See an edit form for that page's markdown.
4. Make changes. Click "save".
5. See the updated changes. Be able to click "edit" and make other changes.

We as admins of the site should be able to see these changes as pull requests and automatically merge them.
## Complications
#### What does a user see when they return to an edited page? Should they be able to see their branches that haven't been merged?

YES
- if they switch to that branch, can they make other edits? Can git switch branches and documentjs generate an HTML page fast enough to get a response out for every request. We might need to cache the docMap and be able to apply a single comments changes to it. This will involve:
- checkout the branch
- getting the file, pulling out the comment that has changed (this might be tricky if it doesn't have a clearly labeled name).
- build the page for that comment using the cached docMap from the "clean" branch.