Merge pull request #1004 from mtrmac/copy-example

Use an inter-registry copy as the example for (skopeo copy)

docs/skopeo-copy.1.md

@@ -86,6 +86,11 @@ Existing signatures, if any, are preserved as well.
 
 ## EXAMPLES
 
+To just copy an image from one registry to another:
+```sh
+$ skopeo copy docker://quay.io/skopeo/stable:latest docker://registry.example.com/skopeo:latest
+```
+
 To copy the layers of the docker.io busybox image to a local directory:
 ```sh
 $ mkdir -p /var/lib/images/busybox