Design opt-in configuration for Packit as a Dist-git CI

[lachmanfrantisek]

For opt-in phases, we need to allow people to try Packit as a dist-git CI.

Let's discuss if we can do this as part of the global configuration Maja has planned as part of packit/research#220

This might also be done separately. Also, we might want to consider that we might need to have a public configuration of the default checks. (For example, we can have a separate git repo with files to opt in and change the list of default checks.)

[lbarcziova]

Here we need to consider:

• what level of configuration do we want to allow? Just listing packages (that could be done also by just editing enabled_projects_for_fedora_ci at the moment, or for better transparency, having a separate repo where users would configure this for themselves that would be synced with our deployment), or we need more granular approach, i.e. allowing packages to opt-in only for particular jobs
• will this be used just temporarily, for the opt-in phase and dropped completely after?

[lachmanfrantisek]

We discussed today at the team architecture meeting that we will avoid implementing a separate UX for a temporary solution to save us some time and let people contribute to the service configuration.

In case of higher demand, we can create a separate UX.