Doc: Update CONTRIBUTING.md with additional information

[minkyraccoon]

Context

ADR-002 recommended a Comos Cash documentation strategy. This issue is part of an epic to implement that strategy.

Good documentation will reduce the time for new devs and users to contribute productively to the project, this includes some of the processes for contributing to the project.

By the end of this issue, there will be some additions to the CONTRIBUTING.md so that

• Some explanation and link to comment formats - (see Docs: Add comment format checks to pre-commit #143)
• Some explanation and link to commit message formats - (see Docs: Add commit message format checks #144)