feat(docker): add image prune alias (#12520)

Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

plugins/docker/README.md

@@ -51,6 +51,7 @@ zstyle ':omz:plugins:docker' legacy-completion yes
 | dii     | `docker image inspect`        | Display detailed information on one or more images                                       |
 | dils    | `docker image ls`             | List docker images                                                                       |
 | dipu    | `docker image push`           | Push an image or repository to a remote registry                                         |
+| dipru   | `docker image prune -a`       | Remove all images not referenced by any container                                        |
 | dirm    | `docker image rm`             | Remove one or more images                                                                |
 | dit     | `docker image tag`            | Add a name and tag to a particular image                                                 |
 | dlo     | `docker container logs`       | Fetch the logs of a docker container                                                     |

plugins/docker/docker.plugin.zsh

@@ -6,6 +6,7 @@ alias dib='docker image build'
 alias dii='docker image inspect'
 alias dils='docker image ls'
 alias dipu='docker image push'
+alias dipru='docker image prune -a'
 alias dirm='docker image rm'
 alias dit='docker image tag'
 alias dlo='docker container logs'