[MNGSITE-541] Define project and subproject

[Bukama]

This uses the definition created in the What's new in Maven 4 article.

[elharo]

spotless is being annoying...

[elharo]

I think if you rebase on master the spotless issues should go away.

[Bukama]

I think if you rebase on master the spotless issues should go away.

I don't get it too. I'm sure I run spotless before I push. Maybe because there are daily snapshots of maven parent from staging repository which are pulled in?

D:\Github\Maven\maven-site>mvn spotless:apply
[WARNING] Unable to find the root directory. Create a .mvn directory in the root directory or add the root="true" attribute on the root project's model to identify it.
[INFO] Scanning for projects...
Downloading from apache.snapshots: https://repository.apache.org/snapshots/org/apache/maven/maven-parent/44-SNAPSHOT/maven-metadata.xml
Downloading from apache.staging: https://repository.apache.org/content/repositories/maven-1906/org/apache/maven/maven-parent/44-SNAPSHOT/maven-metadata.xml
Downloaded from apache.snapshots: https://repository.apache.org/snapshots/org/apache/maven/maven-parent/44-SNAPSHOT/maven-metadata.xml (810 B at 9223372036854775807 GB/s)
Downloading from apache.staging: https://repository.apache.org/content/repositories/maven-1906/org/apache/apache/34-SNAPSHOT/maven-metadata.xml
Downloading from apache.snapshots: https://repository.apache.org/snapshots/org/apache/apache/34-SNAPSHOT/maven-metadata.xml
Downloaded from apache.snapshots: https://repository.apache.org/snapshots/org/apache/apache/34-SNAPSHOT/maven-metadata.xml (589 B at 9223372036854775807 GB/s)
[INFO]
[INFO] ----------------------------------------< org.apache.maven:maven-site >-----------------------------------------
[INFO] Building Apache Maven Site 1.0
[INFO]   from pom.xml
[INFO] ----------------------------------------------------[ jar ]-----------------------------------------------------
[INFO]
[INFO] --- spotless:2.44.2:apply (default-cli) @ maven-site ---
[INFO] Index file corresponds to a different configuration of the plugin. Either the plugin version or its configuration has changed. Fallback to an empty index
[INFO] Spotless.Java is keeping 1 files clean - 0 were changed to be clean, 1 were already clean, 0 were skipped because caching determined they were already clean
[INFO] Spotless.Pom is keeping 1 files clean - 0 were changed to be clean, 1 were already clean, 0 were skipped because caching determined they were already clean
[INFO] Spotless.Markdown is keeping 103 files clean - 0 were changed to be clean, 103 were already clean, 0 were skipped because caching determined they were already clean

However, rebased, applied again.

[elharo]

It wasn't this PR's fault. There was a problem in another file in the repo that caused spotless to fail on all PRs even though that file wasn't edited in this PR. It's now fixed at head, and that's why rebasing let this PR pass.