Example config for publishing to Maven Central

[leonardehrenfried]

This PR adds some example config for publishing to Maven Central.

I'm pleased to say that the publishing process is now a lot more pleasant than it was a few years ago. Sonatype really worked on the DX!

But there are some problems:

Parent POM

I removed the inheritance from the parent POM because it is defining the distribution repository to be camsys-apps.com but we don't want that. If you want to keep using the parent POM then you'd have to change a few things there.

Upload limit

The combined upload to Maven Central is 1.5 GB big which is above the size limit:

https://central.sonatype.org/publish/publish-portal-upload/

I'm not familiar with all these components but there are quite a few *-webapp modules that build large WAR files which are around 200MB each. Are these supposed to be published to Maven Central?

Because of the last point, I haven't actually succeeded in uploading the artifacts.

For reference, this is the command I executed for the deployment:

mvn deploy -DskipTests

cc @aaronbrethorst

[aaronbrethorst]

Super cool thank you @leonardehrenfried! I'll review soon.