[Request?] Retro-border DFC indicators.

[RivalRowan]

Hi @andrewgioia,
The release of Innistrad Remastered is bringing the old frame to double-faced cards for the first time. WotC have decided to add a grey triangle to the faces to indicate which is the front face and which is the back. I'm not sure if these are distinct enough to warrant inclusion in Mana. They are just triangles after all.