The idea

I suggest we introduce a configuration file (at least optionally).

Context

With override levels and disabling inspections we already have possibly quite a few values to configure. Also the syntax for configuration differs for different build systems (Maven, Gradle, sbt). For non-trivial configuration it would be more readable and maintainable to have a separate Scapegoat configuration file (only referred to from build.sbt, pom.xml, etc.)