docs(readme): add example of react-native imports

Author: trivikr

README.md

@@ -77,6 +77,12 @@ to add and import following polyfills in your react-native application:
 - [react-native-get-random-values](https://www.npmjs.com/package/react-native-get-random-values)
 - [react-native-url-polyfill](https://www.npmjs.com/package/react-native-url-polyfill) <!-- Future support in #2138 --->
 
+```js
+import "react-native-get-random-values";
+import "react-native-url-polyfill/auto";
+import { DynamoDB } from "@aws-sdk/client-dynamodb";
+```
+
 ## New features
 
 ### Modularized packages