This is a step towards making the completing-read framework more
easily interchangeable (I'm eyeing selectrum).
Change-Id: I7a066e212a5384136defbba8f11ef9ed57abf22e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2240
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI