[Feature request] Mixed dice type, keep N highest

[patrixl]

Playing Agon, but I suppose this can apply to other games. The game uses multiple dice type to make a dice pool and asks the players to keep the 2 highest dice and add them up.

e.g: roll 2d6 and 1d8 and a d10, keep the 2 highest. Add them up even.

How I imagine the syntax: /r (2d6, d8, d10)k2

If this is already possible, I'm all ears (or eyes)