Create sbt-plugin to package CLI app as GraalVM native Docker image

[jdegoes]

A small and simple SBT plug-in that can package up a CLI application as a GraalVM native docker image would make it much easier to prepare ZIO CLI applications for deployment.

Perhaps this could be a source of inspiration or a component of this solution.

[alterationx10]

I'd like to help with this one!

[alterationx10]

@jdegoes This might have been more complicated in May than it was in August 😄 I have played around with the sbt-native-packager, but there is also the sbt plugin https://github.com/scalameta/sbt-native-image that has recently come out which performs the sorcery of even automatically downloading/installing GraalVM native-image!

Would you recommend still integrating a custom sbt plugin for this, or use this other package?

[jdegoes]

@alterationx10 This looks nice!

Maybe it would be possible to have an SBT plug-in that depends on sbt-native-image, but which can also perform ZIO CLI-specific actions, such as generating the runner/installer script and so forth?

It would be nice to have an SBT task called build-cli or something that performs the full process, resulting in the native image configured appropriately for the CLIApp together with the runner/installer script.

[alterationx10]

There could be some tasks to generate the shell completion as well

[alterationx10]

WIP PR #57 for early discussion