Add a group and description for the runPluginVerifier

[opticyclic]

Problem

It is useful to import your project into other plugin projects to use the plugin verifier.

e.g.

apply from:'https://raw.githubusercontent.com/FWDekker/intellij-randomness/master/gradle/scripts/verifier.gradle'

runPluginVerifier {
    pluginFileName = "$rootProject.name-$version"
    ides = ["IC-2019.3", "IC-2020.1"]
    verifierVersion = "1.241"
}

However, this appears under the 'other' section of gradle tasks.

Suggested solution
Add a Group and Description to the task to make it clearer.
e.g.

   group = 'intellij'
   description = 'Test the plugin for binary compatibility against different versions of IDEA'

Alternative solutions
I can add it manually e.g.

apply from:'https://raw.githubusercontent.com/FWDekker/intellij-randomness/master/gradle/scripts/verifier.gradle'

runPluginVerifier {
    group = 'intellij'
    description = 'Test the plugin for binary compatibility against different versions of IDEA'
    pluginFileName = "$rootProject.name-$version"
    ides = ["IC-2019.3", "IC-2020.1"]
    verifierVersion = "1.241"
}

[fwdekker]

Thanks for the clear issue description!