Announce the final phase of Packit as a Fedora dist-git CI

[lachmanfrantisek]

As part of packit/packit-service#2692, we need to properly communicate the process and how people can try it and provide feedback during the implementation.

After each phase, let's communicate:

• What we achieved. (Cover also incorporated/processed feedback.)
• How can people use the new features.
• How can people provide feedback, ask questions,..
• Recapitulate the plan and schedule.

Ideally, send it (or link it) to:

• https://communityblog.fedoraproject.org/
• discussion.fedoraproject.org
• packit.dev
• our channels
• fedora-ci Matrix channel

[lbarcziova]

Relevant.