Snapshot support

[2V3EvG4LMJFdRe]

I'd say the snapshot is about the second most essential object in the asset folder, only after the boxart, so I'm just posting in hopes that this is considered. I also think there's definitely interest for this by the users - there's actually a theme that implements it, but it's a workaround were the entire image is the box + the snapshot (which is less than ideal).