add compatibility

README.md

@@ -13,6 +13,11 @@
 
 The react-native-agora is an open-source wrapper for react-native developers. This SDK takes advantage of React Native and Agora RTC Video SDKs on Android/iOS.
 
+## Compatibility
+  * react native 0.58.x
+  * iOS SDK 8.0+
+  * Android 5.0+ x86 arm64 armv7a
+
 ## [quick start](https://github.com/AgoraIO-Community/Agora-RN-Quickstart)
 
 ## Installation