To edit the wiki through the Github wiki web interface, which is used by the 'edit' and 'history' links at the top right, you need to be logged into a Github account. http://bottoms.christianjaeger.ch/
is synchronized to the contents at Github every 10 minutes, or when you push the 'sync' button.
Alternatively, you can work on the wiki by cloning its Git repository:
git clone https://github.com/pflanze/bottoms.wiki.git
Github's fork functionality doesn't support the *.wiki.git repositories, though, so you'll have to feed back the changes in some other way, like sending them as patches to one of the Mailing lists (using "git format-patch" and "git send-email"), which should actually be nice since everybody gets a chance to see the changes, or creating an independent repository on your own Github account without the .wiki in its name, and notifying me or, if its of general interest for the group, one of the Mailing lists about it so that I can merge it.
I've written software to convert the wiki checkout to html files locally for previewing. Read bottoms-cfg.pl for details. (Should I create writable personal Git clones with preview on my server? Let's see whether that would be useful enough to warrant the time investment.)
-- Christian.