Split Window Commands

* Ctrl-S        ==> Vertical Split
* Ctrl-Shift-S  ==> Horizontal Split
Move to Opposite Group Keybinding (Cmd-Ctrl-M)
Adds keycaps for Splitting windows

smash + up for split vertically
smash + down for split horizontally
smash + left/right for move to opposite tab group

where smash = Cmd + Opt +Ctrl + Shift