Sunken Skeletons

Adds the aquatic Sunken Skeleton mob from Minecraft Dungeons. These skeletons spawn in biomes defined by the #wich:spawns_sunken_skeletons tag [default minecraft:warm_ocean, minecraft:lukewarm_ocean, and minecraft:deep_lukewarm_ocean]. When killed by a player, they have a chance to drop bubble, fire, or horn coral depending on their variant and more frequently with the Looting enchantment. Skeletons fully submerged in water in one of the biomes defined by the #wich:skeletons_can_become_sunken tag [default the same as the #wich:spawns_sunken_skeletons tag] can also convert into Sunken Skeletons the same way they can convert into Strays in Powdered Snow. Sunken Skeletons' arrows are not slowed down by water.