For blog post about sealed classes, when expressions and custom detekt rule

CustomRulesetProvider.kt

class CustomRulesetProvider: RuleSetProvider {
  override val ruleSetId: String = "detekt-rules"

  override fun instance(config: Config): RuleSet = RuleSet(
    ruleSetId,
    listOf(
      NonExhaustiveWhen(config)
    )
  )
}