adds StackBlitz and updates tutorial link (#35)

* adds StackBlitz and updates tutorial link

Author: conshus

README.md

@@ -1,2 +1,2 @@
 # Vonage Client SDK Tutorials
-Source code for various [Vonage Client SDK tutorials](https://developer.vonage.com/client-sdk/tutorials/).
+Source code for various [Vonage Client SDK tutorials](https://developer.vonage.com/en/vonage-client-sdk/overview).

messaging-js/README.md

@@ -0,0 +1,8 @@
+In-App Messaging tutorial application code using Vonage JS Client SDK
+
+## Demo
+
+[![Open in StackBlitz](https://developer.stackblitz.com/img/open_in_stackblitz.svg)](https://stackblitz.com/fork/github/Vonage-Community/tutorials-client_sdk-ios-android-js/tree/main/messaging-js)
+
+> Note: There is a devDependency `sirv-cli` in the project that is only necessary to run the demo on StackBlitz.
+

messaging-js/package.json

@@ -4,11 +4,15 @@
   "description": "Tutorial Chat application using Vonage Client SDK",
   "main": "chat.js",
   "scripts": {
+    "start": "sirv --dev",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "author": "",
   "license": "ISC",
   "dependencies": {
     "@vonage/client-sdk": "^1.3.0"
+  },
+  "devDependencies": {
+    "sirv-cli": "^2.0.2"
   }
 }