doc: Update README.md

Author: jaywcjlove

packages/core/README.md

@@ -35,7 +35,7 @@ A UI component library based on React Native (Android & iOS).
 ## Install
 
 ```bash
-yarn add @uiw/react-native react-native-svg  react-native-root-siblings
+yarn add @uiw/react-native react-native-svg react-native-root-siblings @react-native-picker/picker
 ```
 
 ## Basic Usage