Ancient City in All Dimensions

MAJOR UPDATE

• fixed strange bug regarding ancient city generation (chunk borders cutting off parts of ancient city)
• readded vanilla ancient cities
• made underground ancient cities way more rarer
• Ancient cities now follow this distribution:

• ancient_city - vanilla ancient cities

• ancient_city_surface - spawns in most biomes, but not oceans and rivers

• ancient_city_underground - spawns in all biomes, also has varied height

• ancient_city_end - spawns in the end highlands biome at y=60

• ancient_city_nether - spawns in all nether biomes except basalt deltas at y=34