Add Code of Conduct

[justaugustus]

Part of #2.
Raised in openclarity/functionclarity#160.

Reference material to consider: https://www.contributor-covenant.org/

Thanks for opening this @justaugustus, once we've got something please let us know and we can pull it into the KubeClarity/ChainClarity repos

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[github-actions]

Thank you for your contribution! This issue has been automatically marked as 'stale' because it has no recent activity in the last 30 days. It will be closed in 15 days, if no further activity occurs. If this issue is still relevant, please leave a comment to let us know, and the 'stale' label will be automatically removed.