Extract jam into dedicated repository

[ForestEckhardt]

jam is being extracted into its own repository in accordance with RFC 0001.

TODO:

• Move jam into its dedicated repo
• Cut release
• Updating tooling to point at the new destination
• Remove jam from cargo and add a message to the README

[sophiewigmore]

@ForestEckhardt will the version of the first jam release be starting from whatever the current version is? Or do you plan to start from v0.0.0?

[ForestEckhardt]

@sophiewigmore I was planning on maintaining that version and just letting them drift but we could also do a major bump @ryanmoran thoughts?

[ryanmoran]

I think you should start over with something like v1.0.0 in the jam repo. Then we can cut a major version of packit when we remove its jam code.

[ForestEckhardt]

I think that jam has been completely successfully extracted. I am going to close this issue. Will reopen if I notice anything missing.