Add pre-commit hooks for black formatting and spell-checking

[bernalde]

Fixes #3895

Summary

Adds optional pre-commit hooks to help contributors catch formatting and spelling issues locally before CI.

Changes

• Add .pre-commit-config.yaml with:
  • black hook (exclusions match pyproject.toml)
  • typos hook (uses existing .github/workflows/typos.toml config)
• Update contribution_guide.rst with setup instructions

Usage (Optional)

pip install pre-commit
pre-commit install

After setup, hooks run automatically on git commit for staged files only.

Legal Acknowledgement

By contributing to this software project, I have read the contribution guide and agree to the following terms and conditions for my contribution:

1. I agree my contributions are submitted under the BSD license.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[mrmundt]

@bernalde - We have been discussing this back and forth for a few weeks. Our primary concern about implementing this is that it adds another file that we need to regularly update the config YAML to ensure it is tracking the most recent versions of typos and black. We always use the most recent version, as soon as it is released, and that means we will be at a minimum forced to update this file monthly because of the release schedule of typos.

We propose a compromise - if you'd like, please make a PR that adds only documentation to the Contribution Guide explaining how someone can turn on pre-commit hooks (with a code block of a sample YAML) PLUS a change to the .gitignore file that ignores the YAML file so it doesn't get accidentally committed to someone's branch.

Thanks!