feat: json output

[zkoppert]

Pull Request

Proposed Changes

fixes #17

This pull request introduces two new files, json_writer.py and test_json_writer.py. The changes implement a new functionality to write contributor data to a JSON file.

Readiness Checklist

Author/Contributor

• [x] If documentation is needed for this change, has that been included in this pull request
• [x] run make lint and fix any issues that you have introduced
• [x] run make test and ensure you have test coverage for the lines you are introducing

Reviewer

• [x] Label as either bug, documentation, enhancement, infrastructure, maintenance or breaking

[zkoppert]

@jmeridth Are we missing any data that you think is important to put into the json output?

[zkoppert]

example outputs for comparison: contributors.json contributors.md