Added and example of using --format with docker images

Docker-DCO-1.1-Signed-off-by: William Henry <whenry@redhat.com> (github: ipbabble)

Signed-off-by: William Henry <whenry@redhat.com>
(cherry picked from commit 798c00a7ee)
Signed-off-by: Victor Vieux <victorvieux@gmail.com>

man/docker-images.1.md

@@ -103,6 +103,43 @@ which displayed different visualizations of the image data. Docker core removed
 this functionality in the 1.7 version. If you liked this functionality, you can
 still find it in the third-party dockviz tool: https://github.com/justone/dockviz.
 
+## Listing images in a desired format
+
+When using the --format option, the image command will either output the data 
+exactly as the template declares or, when using the `table` directive, will 
+include column headers as well. You can use special characters like `\t` for
+inserting tab spacing between columns. 
+
+The following example uses a template without headers and outputs the ID and 
+Repository entries separated by a colon for all images:
+
+    docker images --format "{{.ID}}: {{.Repository}}"
+    77af4d6b9913: <none>
+    b6fa739cedf5: committ
+    78a85c484bad: ipbabble
+    30557a29d5ab: docker
+    5ed6274db6ce: <none>
+    746b819f315e: postgres
+    746b819f315e: postgres
+    746b819f315e: postgres
+    746b819f315e: postgres
+
+To list all images with their repository and tag in a table format you can use:
+
+    docker images --format "table {{.ID}}\t{{.Repository}}\t{{.Tag}}"
+    IMAGE ID            REPOSITORY                TAG
+    77af4d6b9913        <none>                    <none>
+    b6fa739cedf5        committ                   latest
+    78a85c484bad        ipbabble                  <none>
+    30557a29d5ab        docker                    latest
+    5ed6274db6ce        <none>                    <none>
+    746b819f315e        postgres                  9
+    746b819f315e        postgres                  9.3
+    746b819f315e        postgres                  9.3.5
+    746b819f315e        postgres                  latest
+
+Valid template placeholders are listed above.
+
 ## Listing only the shortened image IDs
 
 Listing just the shortened image IDs. This can be useful for some automated