Full GMail keyboard shortcut parity

Hi, I'm exploring mailbox.org as a GMail alternative. Most things seem to be working fine but I'm disappointed by the lack of keyboard shortcuts in the web client for mail, particularly `u` to go back to the mailbox from a message and `j` and `k` for navigating between threads in a mailbox. It would be great if there was full parity with GMail's keyboard shortcuts, and if they can't match GMail exactly, a mode to make them do so would be awesome.

FWIW, the "Group by: conversations" was pretty hard to find. It might just generally be useful to have a "make it as close to gmail as possible" mode for people trying to de-Google.