Mob heads datapack addition

[johndrinkwater]

johndrinkwater> normal rates would be fine to me
Jobe> could make player head drops 100% for player kills
Jobe> any chance you could post a request at https://github.com/Simplanet/Simplanet-Datapack/issues so I dont forget cause I cant get to it right now

[johndrinkwater]

more mob heads from https://vanillatweaks.net/picker/datapacks/ would be a nice drop-in way to support this. Their player head drop pack also adds lore for the killer, which might be nice.