Releases
One way to keep track of major changes to your archive (e.g. adding a large batch of files, overhauling the color scheme, etc.) is using Github’s Releases feature. Not only can this allow you to keep track of major milestones for your archive, but it can also allow you to revert to a stable version of your archive in case of emergency.
For more on creating a release of your archive, see Github’s documentation.