Use of AWS ECR private repo documentation updates (#39)

* Additional documentation on using AWS ECR for private image registry

* Clarification of Docker image in workaround

docs/PubSubPlusOpenShiftDeployment.md

@@ -209,6 +209,7 @@ Deployment scripts will pull the Solace PubSub+ image from a [Docker registry](h
 
 ```shell
     # Required if using ECR for Docker registry
+    # Ensure to use aws cli v1, any sub version
     cd ~/workspace/pubsubplus-openshift-quickstart/scripts
     sudo su
     aws configure       # provide AWS config for root; provide your key ID, key and region.
@@ -228,6 +229,9 @@ Deployment scripts will pull the Solace PubSub+ image from a [Docker registry](h
 
 <br>
 
+> Note: If using MiniShift a workaround is required: running the `addECRsecret.sh` will not be enough and requires manually loading the broker image to MiniShift's Docker. (1) Follow the steps to [configure your console to reuse the Minishift Docker daemon](//docs.okd.io/3.11/minishift/using/docker-daemon.html), then (2) use the `docker pull` command to pull the target image from ECR. Ensure to use the exact same image URI as will be passed to the broker deployment in next Step 6. Finally (3) use `eval $(minishift oc-env)` to ensure the [oc binary is added to your PATH](//docs.okd.io/3.11/minishift/openshift/openshift-client-binary.html#openshift-client-binary-overview).
+
+
 For general additional information, refer to the [Using private registries](https://github.com/SolaceProducts/pubsubplus-kubernetes-quickstart/blob/master/docs/PubSubPlusK8SDeployment.md#using-private-registries) section in the general Event Broker in Kubernetes Documentation.
 
 ### Step 6-Option 1: Deploy the event broker using Helm