Only one is enabled in the terminal repl, but none when we use ciel as a regular Lisp library. We don't want to mess with the readtables by default. (see below

Only one is enabled in the terminal repl, but none when we use ciel as a regular Lisp library. We don't want to mess with the readtables by default. (see below to enable the shell passthrough in your editor's REPL)