Update README.md

README.md

@@ -12,6 +12,8 @@ yarn add react-native-view-shot
 react-native link react-native-view-shot
 ```
 
+Make sure react-native-view-shot is correctly linked in XCode (might require a manual installation, refer to [React Native doc](https://facebook.github.io/react-native/docs/linking-libraries-ios.html)).
+
 ## Recommended High Level API
 
 ```js