I want tmux to work more like vim, i.e. there's a normal mode and an insert mode. Tmux has keytables, and supports custom keytables, so I can bind Escape -T insert to switch to Normal mode, but what is the command for normal mode? How do I actually use a custom keytable? switch-client -T <mode> says it will use keytable <mode> for the next keypress, but how do I get it to use that one keytable for all keypresses (until one of the keypresses uses the same command to switch modes again)?