This forces GitHub to always use SSH, even for HTTPS URL's! This way, you can use
https:// GitHub URL's and they will still use your SSH key.
When you clone an HTTPS URL, it now gets rewritten as an SSH URL.
This URL will get rewritten to access via SSH instead of HTTPS. It will instead be fetching from [email protected]_ via SSH.
Alternatively, this forces GitHub to always use HTTPS. Great for macOS, where you can use git-credential-osxkeychain to store your GitHub token.
This will not rewrite
[email protected]com:user/repo.git URL's, though, so I don't really recommend it! Besides, SSH keys are often easier to manage than API tokens.
Hat tip to these people!