Add magic plugin for kotlin

[tlf30]

Sorry guys, I have had a busy summer and have not got to this yet, iirc @Major- had some work on this started. I probably won't be able to get to this for a few months still. Does someone want to tackle the magic plugin?

[Major-]

I've got some local work, but we've decided to focus on merging kotlin-experiments (and leave magic for after that), unless it's as an external contribution.

[tlf30]

That sounds good to me