Welcome to the cosycat.wiki repository. The reason why this exists is basically to support a pull-request based approach to wiki editing (by default GitHub-wikis will only allow either edits by project collaborators or by anyone - which you can configure in the main repository settings).
Here, we instead follow the approach described here, which can easily be extended to the approach described here for automatic sync of merged pull-requests using CI builds.
If you want to collaborate, you need to fork this repository (https://github.com/emanjavacas/cosycat-wiki), and issue a pull-request with your edits.