Add Icelandic speaker diarization recipe

[judyfong]

This github repo uses the kaldi recipe to create and train speaker diarization for Icelandic and it obtains results, at least for Icelandic, that are 5% better than the default diarization recipes in the kaldi-asr repo.

As an aside, there doesn't seem to be a place for diarzation models within this repo. Is that because models are too dependent on each framework to be shared independently?