Better jungle generation

Jungles are very interesting biomes, but they could use some improvements. They should be renamed to rainforests, since “jungle” is the word for the floor of a rainforest. It could be divided into layers, with different mobs spawning in different layers. Pigs and cows would spawn in the bottom, and parrots higher up. Jungle trees should be denser, and oak trees should be removed. Jungle wood could be renamed Cacao wood since cocoa pods grow on them. Finally, sources of water and rivers should generate more frequently.