update readme es6 usage

Author: salvoravida

README.md

@@ -95,6 +95,28 @@ function RecognizerStop(SDK, recognizer) {
 }
 ```
 
+## ES6 Module Usage
+```javascript
+import * as SDK from 'microsoft-speech-browser-sdk';
+
+function RecognizerSetup(recognitionMode, language, format, subscriptionKey) {
+    let recognizerConfig = new SDK.RecognizerConfig(
+        new SDK.SpeechConfig(
+            new SDK.Context(
+                new SDK.OS(navigator.userAgent, "Browser", null),
+                new SDK.Device("SpeechSample", "SpeechSample", "1.0.00000"))),
+        recognitionMode, // SDK.RecognitionMode.Interactive
+        language, // Supported laguages are specific to each recognition mode. Refer to docs.
+        format); // SDK.SpeechResultFormat.Simple (Options - Simple/Detailed)
+
+    // Alternatively use SDK.CognitiveTokenAuthentication(fetchCallback, fetchOnExpiryCallback)
+    let authentication = new SDK.CognitiveSubscriptionKeyAuthentication(subscriptionKey);
+
+    // return SDK.Recognizer.Create(recognizerConfig, authentication);
+    return SDK.CreateRecognizer(recognizerConfig, authentication);
+}
+```
+
 ## Try the sample out
 What to try the sample ? All you need is a subscription key. [Sign up](https://www.microsoft.com/cognitive-services/en-us/sign-up) to get one.