feat: update validate_copyright to work as pre-commit hook

[MyuddinKhatri]

Issue - https://github.com/agritheory/test_utils/issues/40 Update validate_copyright to work as pre-commit hook To use this as pre-commit hook -

  - repo: https://github.com/agritheory/test_utils/
    rev: {rev}
    hooks:
      - id: validate_copyright
        files: '\.(js|ts|py|md)$'
        args: ["--app", "cloud_storage"]

[Alchez]

@MyuddinKhatri The snippet you've shared in the description should go into this repo's readme file ideally

[MyuddinKhatri]

@MyuddinKhatri The snippet you've shared in the description should go into this repo's readme file ideally

@Alchez @agritheory I added the docs please check.