Please provide better documentation

[cryptomilk]

Please provide better documentation for this module with examples.

For example, I'm trying to create a tarball from a git repo and try to exclude some sample files. I've only found out that an exclude tag exists by checking https://github.com/openSUSE/obs-service-tar_scm/blob/master/tar_scm.service.in

However the documentation is so sparse it isn't clear how to use that exactly. I specified it in the tar_scm service but that it didn't work. You need to specify it in the tar service.