Add a subcommand for rpmautospec (e.g. rpmautospec onboard or rpmautospec migate) that, when run in a dist-git repo, or with the path to a specfile as the first argument, will perform a basic conversion to rpmautospec:

• replace Release with %autorelease (this could also perform additional checks to either automate more complex uses, or abort and print an error in that case)
• create a changelog files with the current changelog and replace it with %autochangelog in the specfile

Additionally, it would be useful to have another command (say, rpmautospec render-changelog) that, when run against a package that's already using rpmautospec, will render the current changelog and update the changelog file with it. The purpose being to automate this process when one needs to manually fix something in the changelog.