Extend Code Ownership Checker configuration

[ekadlecova]

The current configuration creates a default team in a git config file and we're probably going to expand to multiple teams and other details.

The intent here is to extend and introduce a decent configuration level:

1. Introduce multiple teams configuration instead of just one team
2. With step 2 we can also have a configuration of the GitHub username or more users and teams

Extending configuration can be also useful for future ideas like blacklist or ignore certain folders or files that the code owners will never cover.