Maven archetype for a Java library set up to publish to Maven Central: Error Prone/NullAway, Spotless, Checkstyle, a 100% JaCoCo coverage gate, GitHub Actions CI/release/Pages workflows, JReleaser, and the usual community-health files - the reusable scaffolding behind li.selman:null-markeder, extracted so a new library starts from `mvn archetype:generate` instead of twenty hand-copied files.