I have a lot of little projects, and while the source code is on git, the other files are in some folder somewhere. Can I ask here how to keep track of those files (prototypes, text files, some images…) ?
If your question is about the best practice to track prototypes, configurations and non code related resources in source control then I believe this is an on topic question for the main site.
Please try however to be clear in your question about what exactly you are trying to do and provide at least one suggestion or idea that you have thought about or tried, or what you are currently doing now and why you don't think this is working well for you. The more detail you provide the better chance it will be well received by the community.