docs: adding pre-commit functionality

[amdove]

• Add pre-commit to repository. Replaces old custom post-checkout hooks that were unused as far as I can tell. Currently only runs format and lint, and tests for each area only if changes are made.
• Updated docs and just recipes to support this, and included information on how to bypass if needed.
• Cleaned up CONTRIBUTING vs README confusion, README is for users of ptd cli, CONTRIBUTING has additional information for developer set up.

Description

Category of change

• Bug fix (non-breaking change which fixes an issue)
• Version upgrade (upgrading the version of a service or product)
• New feature (non-breaking change which adds functionality)
• Build: a code change that affects the build system or external dependencies
• Performance: a code change that improves performance
• Refactor: a code change that neither fixes a bug nor adds a feature
• Documentation: documentation changes
• Breaking change (fix or feature that would cause existing functionality to not work as expected)