Add/code of conduct

[jeffpaul]

Description of the Change

This PR adds a code of conduct to the repo to help explain how people are expected to conduct themselves within the project. Similar to #283 we'll want to look to merge #282 first and then refresh this PR with the .distignore reorganization.

Note that this set [email protected] as the contact email, so if that should change we'll want to update the PR.

Alternate Designs

Keep as-is without a code of conduct, or select an alternate code to use.

Benefits

Ensures there's a described way we expect people to act within the project.

Possible Drawbacks

None identified.

Verification Process

Manually verified via VS Code and GitHub Desktop UI.

Checklist:

• [ ] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests passed.

Applicable Issues

none identified

Changelog Entry

### Added
- Documentation