Add README

examples/tips/README

+C++ Client implementation for Cloud Pub/Sub service (TIPS)
+(https://developers.google.com/apis-explorer/#p/pubsub/v1beta1/).
+
+"Google Cloud Pub/Sub" API needs to be enabled at
+https://console.developers.google.com/project to open the access for a client. 
+Select the project name, select the "APIs" under "APIs & auth", and turn
+on "Google Cloud Pub/Sub" API. 
+
+To run the client from Google Compute Engine (GCE), the GCE instance needs to
+be created with scope "https://www.googleapis.com/auth/cloud-platform" as below:
+
+gcloud compute instances create instance-name 
+    --image debian-7 --scopes https://www.googleapis.com/auth/cloud-platform
+   
+To run the client from GCE:
+make tips_client
+bins/opt/tips_client
+    
+A service account credential is required to run the client from other
+environments, which can be generated as a JSON key file from
+https://console.developers.google.com/project/. To run the client with a service 
+account credential:
+
+bins/opt/tips_client
+    --service_account_key_file="absolute path to the JSON key file"
+    --project_id="your project id"
+
+    
+
+