I am currently adding source and test source directories as follows:
val modifiableModel = ModuleRootManager.getInstance(module).modifiableModel
val contentEntry = modifiableModel.addContentEntry(contentRoot)
However, I can't find how to specify a resource or test resource dir (I expected to find something like `addResourceFolder(dir, isTest: Boolean)` but no such thing.
How do I add a resource directory to my module?