add gradle tasks to publish to local Maven repository and remote Sonayype Nexus repository

[plotters]

[kiview]

Hi, thanks for the PR. We want a release process that's similar to the one of testcontainers-java. So we'd need something like the deploy.sh file as well I assume.

[plotters]

This is for a gradle build, I don't use maven

[kiview]

Of course, I don't plan to add Maven build support for this project, it's more for the general signing and pushing strategy, involving the Maven Nexus secrets.