Added new texture sizes, included explanation in asset description

Added 1028 and 512 variations. These will be lower in visual quality. 

All textures were created using 128 or 256 images, but then baked to a larger texture size to preserve visual quality, so with the highest texture sizes there is no actual difference in the way that the original images appeared vs the baked texture. The larger size simply allows it to retain the visual quality of each image without using multiple images in multiple material slots. If you want what it "Actually looked like" then use the largest texture size.