Make changes based on PR #4 feedback: Clean Configuration Management, OOP, and Testing + Maybe stylistic changes

[ilgaur]

I'm following code review feedback from PR #4, trying to implement requested improvements.

Major:

• Cleaner configuration management #9
• Think about the tradeoffs of replacing subprocess calls with a Git library and abstract away those commands and maybe make it optional too
• OOP restructuring
• Unit tests

Minor:

• Update .pre-commit-hooks.yaml to reference original remote repo URL
• Add a .pre-commit-config.yaml or explain how to create and use it in the README
• Add args and additional_dependencies explicitly to .pre-commit-config.yaml. (Envs is mentioned at the top on the major issues because it probably needs more work and is tied to other tasks)