Found it, thanks!
THe editor seems a bit confusing though. Is there a manual or tutorial or anything?
I'm wondering if enemies, monster lairs, treasure chests, and shards are generated randomly on the map when I start a new game using that custom map editor map? Or do I have to manually place every monster, every lair, every treasure chest, etc? It would be an incredible pain to create large or huge maps if I had to manually put in hundreds of chests, lairs, etc.