Add instructions to show Docker extension system container (#15018)
Add instructions to show Docker extension system container (#15018)

* Add instructions to show Docker extension system container

* Update desktop/extensions.md

Co-authored-by: Allie Sadler <3ab59c325e83a6f4d1c968ddfef82238a4ecdc43@users.noreply.github.com>
thaJeztah/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io