How to build intellij_master branch standalone

[pbi-qfs]

Short description

The intellij_master branch is now the one receiving all the updates, and the master branch is left far behind (and, for example, does not directly compile with IntelliJ 2022.1.2 anymore without cherry picking ccaf269 from intellij_master).

Is there any instruction on how to build the plugin standalone from the intellij_master branch? The gradle tasks normally used are not available in that branch, and compiling IntelliJ completely seems not to be a simple thing to do.

Expected behavior

There should be a page explaining how to build the lombok plugin from the branch receiving all the updates, since it seems not to be straightforward from the traditional build path. This also simplifies receiving bugfix pull requests from the community.