I'm very new to version control and git, and I'm trying to learn how to use SourceTree. I have about a dozen commits already and I'm not sure why or how these .baml files were created, but they were not in any of my previous commits, and I'm wondering if can stop tracking and ignore them or not.
If I understand what I've read about baml files is that they are created at runtime so I would think they aren't necessary to track, right?
Wikipedia says they are binary files and it seems as though they are a byproduct of the actual coding work you're doing. In other words, as you say yourself, you didn't create them, so it'd be safe to ignore them (simply add the following line to the .gitignore file in the root of your repository *.baml).
In general, you should use git to keep track of text files you're actually changing. There are, of course, project-specific exceptions to this, but your case doesn't seem to be one.