Mention `codespell` in CONTRIBUTING.rst ?

[psadil]

Summary

While I was working on a pull request, typos were found by codespell. I see that there is a github action for running codespell on all pull requests to master. Would the maintainers consider a new pull request for an addition to CONTRIBUTING.rst that mentions running codespell prior to submitting a pull request, e.g., in this section?

Platform details:

Choose one:

• [x] Local environment

• [ ] Container

• Heudiconv version: 0.12.0