update caves, caves_dunes

use sandstone and stone on dunes, enlarge some filler depths

mapgen.lua

@@ -74,11 +74,11 @@ add_biome("fiery", nil, "ethereal:fiery_dirt", 1, "default:dirt", 3,
 add_biome("fiery_ocean", nil, "default:sand", 1, "default:sand", 2,
 	nil, nil, nil, nil, nil, -192, 4, 100, 0, ethereal.fiery)
 
-add_biome("caves_dunes", nil, "ethereal:crystal_moss", 3, "air", 8,
+add_biome("caves_dunes", "default:desert_sand", "default:sandstone", 6, "air", 8,
 	nil, nil, nil, nil, nil, 32, 120, 10, 2, ethereal.caves)
 
-add_biome("caves", nil, "default:desert_stone", 3, "air", 8,
-	nil, nil, nil, nil, nil, 4, 32, 10, 2, ethereal.caves)
+add_biome("caves", nil, "default:desert_stone", 4, "air", 8,
+	nil, nil, nil, nil, nil, 4, 31, 10, 2, ethereal.caves)
 
 add_biome("caves_ocean", "default:gravel", "default:sand", 3, "air", 8,
 	nil, nil, nil, nil, nil, -14, 3, 10, 2, ethereal.caves)