added readme.md tutorial video. (#336)

Author: stephenlb

README.md

@@ -14,6 +14,12 @@ PubNub takes care of the infrastructure and APIs needed for the realtime communi
 
 You will need the publish and subscribe keys to authenticate your app. Get your keys from the [Admin Portal](https://dashboard.pubnub.com/login).
 
+## Tutorial Video
+
+[![Getting Started with PubNub JS SDK](https://replayable-api-production.herokuapp.com/replay/64ee0d2ca4bc310061f566ca/gif?shareKey=8YQoHC40jdzYpYGpcJhQ)](https://app.dashcam.io/replay/64ee0d2ca4bc310061f566ca?share=8YQoHC40jdzYpYGpcJhQ) 
+
+Watch [Getting Started with PubNub JS SDK](https://app.dashcam.io/replay/64ee0d2ca4bc310061f566ca?share=8YQoHC40jdzYpYGpcJhQ) on Dashcam
+
 ## Configure PubNub
 
 1. Integrate the JavaScript SDK into your project: