Scuttlebutt is built on immutable append-only logs; it doesn't have editable #wiki pages. But they can be built on top using Annah.
A smart link to a wiki page is a reference to the Annah program that renders it. Of course being a wiki, there will be more smart links on the wiki page going to other wiki pages, and so on.
The wiki page includes a smart link to edit it. The editor needs basic form support in the Scuttlebutt client; when the edited wiki page is posted, the Annah program diffs it against the previous version and
Edit which gets posted to the user's feed. Rendering the page is just a matter of finding the
Edit messages for it from people who are allowed to edit it, and combining them.
Anyone can fork a wiki page by posting an
Edit to their feed. And can then post a smart link to their fork of the page.
And anyone can merge other forks into their wiki page (this posts a control message that makes the Annah program implementing the wiki accept those forks'
Edit messages). Or grant other users permission to edit the wiki page (another control message). Or grant other users permissions to grant other users permissions.
There are lots of different ways you might want your wiki to work. No one wiki implementation, but lots of Annah programs. Others can interact with your wiki using the program you picked, or fork it and even switch the program used. Subjectivity again.