Establish/document process for changes and configure snapshot publishing

[jjohannes]

We need a (official) process for making changes to the plugins if required by a certain repository. Hopefully, this should be an infrequently used process. But nonetheless, it should be clear and not too complicated so that potentially each developer having the need for a change in the Gradle configuration can follow it.

This issue describes a rough process here in the description. To resolve this issue, this should be put into the documentation and extensions to the build that are required – such as SNAPSHOT publishing – should be performed.

• (1) Local: Do changes and test them locally
  • Clone the hiero-gradle-conventions repository
  • In the repository where you need the change, add to settings.gradle.kts:
    pluginManagement { includeBuild("<path-to-hiero-gradle-conventions">) }
    The plugins are now used from source, the plugins are shown in IntelliJ next to the project
  • If applicable, also add a test in hiero-gradle-conventions/src/test/kotlin
• (2) PR in this repo: Once changes are ready, create a PR with the changes in hiero-gradle-conventions
  • Once PR is merged, a snapshot of the plugins should be published automatically
  • As the Gradle plugin portal does not support snapshots, these should be published to Maven Central
    • TODO configure SNAPSHOT publishing to Maven Central from main
• (3) PR ins other repo: In the project that needs the changes, create a PR that initially uses the latest snapshot and does any changes required in the other repo
  • For snapshots to work, add to settings.gradle.kts:
    pluginManagement { repositories.maven("<path-to-hiero-gradle-conventions">) }
    and change the version of plugins { id("org.hiero.gradle.build:<version>")} } accordingly.
  • Make sure changes work as expected on CI before proceeding to (4)
• (4) Publish new version of hiero-gradle-conventions: Before the PR (3) is merged...
  • Publish a new version of the plugins to Gradle Plugin Portal by pushing a version tag
  • Switch to the the new stable plugin version in the PR (3) before merging it