End dimension update

New island generation. Right now the End islands are for the most part very flat and lack personality. I think that having islands generate at varying heights or depths could be one easy solution. It would add more interactions for players since they would have to think about ways to get up or down to new islands instead of just across. City generation. Current End cities are nice for loot but can be sort of repetitive. One solution to make them more exciting is adding a rare stronghold type city where the city is a bit larger then normal and includes parts that generate into and throughout the island itself (kind of like some nether fortresses). A new block that could be added and included in new island generation could be new crystal blocks. These crystals could be inspired by these real world formations: https://www.bbc.com/travel/article/20220721-the-worlds-largest-crystal-cave They could generate inside small island caves, stick out from the terrain in ominous ways, or hang down from the bottom of the end islands making it so only the bravest of players risk collecting them. Possible uses could include: decoration. Maybe a cool interaction between light sources. Or a very cool interaction is something you might get from breaking them down into powdered crystal. This powdered crystal could be used in potions to unlock new effects or power up current ones even more! Another possible use could be a new resource for enchanting