Why might I need the "idea" Gradle plugin?

(new to IntelliJ)

I read about this in the past couple of days.  Some old IntelliJ hand said somewhere that you should always include it in build.gradle.

I don't think they may mean this:

"id 'org.jetbrains.intellij' version '0.4.16'" as documented here.  On the face of it, that seems to be devoted to the development of Intellij IDE plugins.

Instead, I believe they mean this:

"id idea" as documented here.