New Visibility Type: Ethereal

[Zoraste]

Don't know if this is the right place, but I'm gonna try it anyway; I'd like to propose a sixth visibility condition of Ethereal. Currently I don't know of a good way to manage seeing creatures on the Ethereal plane in 5e, but this module seems perfect if it could be added. Maybe make it so creatures with the Ethereal condition can only be seen by other Ethereal creatures or creatures with Truesight if possible.

Just some feedback, great module otherwise, had a lot of good use out of it already.