Questions on usage of GitHub would ordinarily be off-topic since it is a website
What you describe in your question sounds like asking how to use GitHub for a particular use- documenting system administration. While system administration is on topic here, writing up how to do it on a website is not (cf the famous- 'boats for programmers' test).
Of course, if you have questions about how local programs on your computer interact with GitHub (eg git or ssh for managing keys), those kinds of questions may well be on topic here.
Your question might be on topic on WebApps
Their github tag reads:
Hosting service for software projects using the Git revision control system. For questions about using GitHub web interface such as: how to use its search, pushing your branch or repository, wiki page formatting and directories, and syntax highlighting on README files.
It sounds like this might cover your use case.