docs(readme): fixup docs for building dev registry

Author: slack

README.md

@@ -6,36 +6,58 @@ This Docker image is based on the official docker distribution image.
 
 Please add any [issues](https://github.com/deis/registry/issues) you find with this software to the [Distribution Project](https://github.com/docker/distribution).
 
-
 ## Deploying
 
-To build a dev release of this image, you will also need your own registry, but DockerHub or Quay will do fine here. To build, run:
+If you want to use the latest registry image built by they Deis team you can simply start a registry via `make deploy`.
+
+If however, you want to build and use a custom image see the instructions below.
+
+## Build and Deploy
+
+To build a dev release of this image, you will also need a registry to hold the custom images. This can be your own registry, Dockerhub, or Quay.
+
 
+First, configure your environment to point to the registry location.
+
+```console
+$ export DEIS_REGISTRY=myregistry.com:5000  # or quay.io, if using Dockerhub, leave this unset
+$ export IMAGE_PREFIX=youruser/             # if using Quay or Dockerhub
 ```
-$ export DEIS_REGISTRY=myregistry.com:5000
+
+To build and push the image run:
+
+```console
 $ make docker-build docker-push
 ```
 
-This will compile the Docker image and push it to your registry.
+Before deploying your custom image you must update the container image specification in the pod manifest. This file is found at `contrib/kubernetes/manifests/registry-rc.yaml`:
+
+```yaml
+        - name: registry
+          image: quay.io/youruser/registry:git-f5c7dc3
+          env:
+            - name: REGISTRY_STORAGE_DELETE_ENABLED
+              value: "true"
+```
 
-After that, run
+Once updated, deploy the registry to your kubernetes cluster with:
 
 ```
 $ make deploy
 ```
 
-Which will deploy the component to kubernetes. After a while, you should see one pod up with one running:
+After a while, you should see one pod up with one running:
 
 ```
 NAME                  READY     STATUS    RESTARTS   AGE
 registry-6wy8o        1/1       Running   0          32s
 ```
 
-You can then query this pod as you would with any other Kubernetes pod:
+You can then interact with this pod as you would with any other Kubernetes pod:
 
 ```
 $ kubectl logs -f registry-6wy8o
-$ kubectl exec -it registry-6wy8o psql
+$ kubectl exec -it registry-6wy8o sh
 ```
 
 ## License