recommend using `docker container prune`, but show an example on
how to combine commands with a bit more context and warnings
about portability/compatibility.
Thanks to Charlie Arehart to do the initial work on this.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit d051df9943)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>