As I work on concepts for games, I produce snippets of interesting media... Which aren't necessarily useful for the game, or optimized for it. In a proper game development environment, there would be various repositories for art, assets and so on.
I am not a professional artist, just a programmer who needs some art to do some of the things I do. Well, and a beginning amateur artist.
However, I also believe strongly in putting my work in progress into Git.
This repo is a combination of Affinity Designer files (.afdesign), Corel Paint (.rif), Affinity Photo and possibly others. Plus of course standard file types like .txt, .png and so on.
In general, I make new things that I create CC0 where I can, and very permissively licensed when I can't manage CC0. I'll try to tag any directory with the license for that content - but if you can't find something declaring that specific content to have a specific license, you may need to ask.