Allow parsing to class with default parameter

[thedevstone]

case class case class Program(name: String, id: Int, active: Boolean = false) extends AlarmEntity yaml

zone:
   name: String
   id: Int

[TimoMeijer]

This does not have to do with circe-yaml, but with the circe Decoders. This functionality is already available, for reference see: https://circe.github.io/circe/codecs/custom-codecs.html#custom-key-mappings-via-annotations