The GitHub Repos module displays a simple list of GitHub repositories on your site.
In the module setting, you need to fill in 3 fields:
To get the values for Client ID and Client Secret, login to your GitHub account and navigate to the Account Settings and then Applications. Under Developer Applications, register a new application. Set both URLs simply to the URL of your Joomla! website, and name the application as you wish. Once the application is saved, the application page will list the Client ID and Client Secret in the top right.