Add the ability to set keybindings

First off just want to say this is a real nice project. 

I wonder if it would be possible to make it so that the keybindings can be customised? 

We would like "enter" to run a command / activate it. 
and also would like "escape" or "q" for exiting. 

Also the quit keybind is not shown along the bottom which is not great for users not familiar with the interface :) 