Publishing on Sonatype

[kubukoz]

Hi!

I see the latest versions are being published on github packages, but it's a relatively high bar for using a small plugin (clients need to set up credentials etc., which can be problematic if they don't already do that on CI) - would you be interested in changing the setup to publish on Sonatype/maven central? It's quite easy with sbt-ci-release, and I can help with that if needed.