add react-native linking info for react-native-voice

Author: spoeck

README.md

@@ -11,7 +11,7 @@ A React-Native Bridge for the Google Dialogflow AI SDK.
 
 Support for iOS 10+ and Android!
 
-We are currently working on dialogflow V2 support! (The beta will be published at 8.March 2018 at the latest)
+We are currently working on dialogflow V2 support! (Last Update: 06.March 2018)
 
 
 [Dialogflow](https://dialogflow.com/) is a powerful tool for building delightful and natural conversational experiences. You can build chat and speech bots and may intergrate it in a lot of platform like twitter, facebook, slack, or alexa.
@@ -24,6 +24,7 @@ npm install --save react-native-dialogflow
 
 react-native link react-native-dialogflow
 react-native link react-native-speech-to-text-ios
+react-native link react-native-voice
 ```
 
 ### iOS: IMPORTANT xCode plist settings