I've been seeing increasing interest and activity around using GitHub for non-code projects, for example Lincoln Mullen's Profhacker post on How to fork a syllabus on GitHub. So I want to take a reading on how ready DHers in general are to use GitHub in that way, and even more, to fork a project, make changes both by adding files (similar to Zotero group functionality) and editing existing files (similar to wiki functionality), and issue a pull request to bring the changes back into the original repository.
As an example, I'm considering putting together a big set of materials useful for doing Omeka training sessions. I'd invite people both to add their handouts or files, and edit the list of possible lessons and activities, which are in a markdown file (again, Lincoln Mullen has a Profhacker post: Markdown: The syntax you probably already know. It will also include code samples and activities, which is what first made me think of GitHub. In theory, intro to Omeka materials could be built up this way. But practically, would I lose too many potential contributors?