Lots of Examples
You can find a lot of usage examples on GitHub.
The stuff in there probably looks a bit weird, unless you are used to cram tests, but they are all tested under CI, so things that work in there will work and things that are broken in there, are expected to be broken.
Again, they aren't very user friendly, but they do provide a bunch of example config files and they each exercise a different bit of InteinFinder's functionality. So, if you need some more examples, feel free to check them out.