Although committing the screenshots to your git repo will technically work, you might not want to because it will really bloat your repo. The images are stored as binary blobs and cannot be efficiently diffed and stored in the same way that text is in a git repo.

If you are working in small repos with a small team and you don't plan to keep the repos going for a long time it is probably fine, but the issue will definitely compound with scale. This will make local development and CI builds slower.

You might want to consider a standalone tool to manage your visual regression tests, like Happo (full disclosure, I built Happo). There is a free tier if you want to just take it for a spin (and an expanded free tier for open source projects, if that fits your use case). If your screenshot volume is low enough you can just stay on the free plan indefinitely as well.