Create a script for automatic Packit config setup in dist-git

[lbarcziova]

This should be the first step in helping maintainers setting up Packit for their packages for Fedora release automation.
This script could be later used in a more automated way.

The script should:

• generate the Packit config
  • think about what should be the input: package name, upstream project URL, upstream_tag_template (this could be also guessed by checking tags in upstream project)
  • choosing which jobs to configure (only pull_from_upstream/whole pipeline)
• push to dist-git rawhide branch / create PR (this could be an input argument)

[lbarcziova]

Notes from discussing this with @xsuchy : this could be also a template with a well-described guidance text what to fill in where.

[lbarcziova]

After thinking about this a little bit more, I think there are 2 types of usecases we want to help with:

1. user setting up Packit for the first time who doesn't know any of the configuration specifics - for that, the template with guidance seems to be a good fit (or some interactive script with guidance questions)
2. user who already used Packit and wants to set it up for a lot of packages with as few manual steps as possible, in an automated way: for that the script with few input values such as URL, tag_template, changelog_style that directly pushes it to dist-git seems like a fit