A small End update within the vanilla framework

Personally, I think the end dimension should remain a mysterious, empty wasteland. So, it could be diversified a bit. Don't add new biomes, a ton of different mobs, new ores, and anything as large-scale as we did with the nether. We could add a couple of new structures that fit the bill, from structures on the scale of desert wells to structures on the scale of desert pyramids. Maybe add arrows that teleport the target to a specific location when they hit. It would also be nice to update the portals to the main island. Although, a few more new mobs that fit the bill wouldn't hurt either.