list state `ready` for filtering in stack_ps.md
list state `ready` for filtering in stack_ps.md

Signed-off-by: SimonHeimberg <7a57b41656be50984d76476b62734727e44a2d50@heimberg-ea.ch>
(cherry picked from commit 6a20e87ae8e32287523bd5aa75ec63d670762ea5)
Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

cpuguy83/cli,docker/cli,cpuguy83/cli,docker/cli,thaJeztah/cli,thaJeztah/cli