Update Contribution Guidelines for Wider Community

What does this MR do?

The contribution guidelines reference an out-of-date label and use incorrect filtering query string values.

This is most likely because this file was taken from the monolith. But since then that file has been revised into a whole contributing documentation set.

This change updates links, references to the label and descriptions of its use.

TODO

• Feature flag
  • Added feature flag:
  • This feature does not require a feature flag
• I added the Changelog trailer to the commits that need to be included in the changelog (e.g. Changelog: added)
• I added unit tests or they are not required
• I added acceptance tests or they are not required
• I added documentation (or it's not required)
• I followed code review guidelines
• I followed Go Style guidelines