Add the rmi flag to podman-run to delete container image

The --rmi flag will delete the container image after its execution
unless that image is already been used by another container(s).

This is useful when one wants to execute a container once and remove
any resources attached to it.

Signed-off-by: Boaz Shuster <boaz.shuster.github@gmail.com>

docs/source/markdown/podman-container-cleanup.1.md

@@ -22,6 +22,14 @@ to run containers such as CRI-O, the last started container could be from either
 
 The latest option is not supported on the remote client.
 
+**--rm**
+
+After cleanup, remove the container entirely.
+
+**--rmi**
+
+After cleanup, remove the image entirely.
+
 ## EXAMPLE
 
 `podman container cleanup mywebserver`

docs/source/markdown/podman-run.1.md

@@ -689,6 +689,11 @@ Note that the container will not be removed when it could not be created or
 started successfully. This allows the user to inspect the container after
 failure.
 
+**--rmi**=*true|false*
+
+After exit of the container, remove the image unless another
+container is using it. The default is *false*.
+
 **--rootfs**
 
 If specified, the first argument refers to an exploded container on the file system.