Add Docker Hub images to readme

Signed-off-by: Ben Firshman <ben@firshman.co.uk>

README.md

@@ -23,3 +23,12 @@ Since this app makes use of Compose's experimental networking support, it must b
     $ docker-compose --x-networking up -d
 
 The app will be running on port 5000 on your Docker host, and the results will be on port 5001.
+
+Docker Hub images
+-----------------
+
+Docker Hub images for services in this app are built automatically from master:
+
+ - [docker/example-voting-app-voting-app](https://hub.docker.com/r/docker/example-voting-app-voting-app/)
+ - [docker/example-voting-app-results-app](https://hub.docker.com/r/docker/example-voting-app-results-app/)
+ - [docker/example-voting-app-worker](https://hub.docker.com/r/docker/example-voting-app-worker/)