Your question may be welcome here on Super User if it does not fall into the following:
Account or shop related issues
These should be addressed directly at GitHub Support.
GitHub interface and features
Better on Web Applications.
For such questions as
- How to use its search
- Wiki page formatting and directories
- Syntax highlighting on README files
Git version control of hosted GitHub repo
Here or on Stack Overflow.
- Includes pushing your repo or branch
- Configuring Git to connect with GitHub
For questions about the Git version control system itself, please use the git tag.