shoe: print tab options less eagerly
shoe: print tab options less eagerly

Turns out that having these pop up on every tab-press is really annoying,
and you usually only want them when it didn't manage to autocomplete anything.
ngzax/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit