docs: add prebuild command and small example app.js (#1)

Signed-off-by: blu3beri <berend@animo.id>

README.md

@@ -76,8 +76,62 @@ Then add the plugin to your Expo app config (`app.json`, `app.config.json` or `a
 }
 ```
 
+And lastly, prebuild the application so the indy-sdk can be added as native dependency (If you aren't making any manual modification to the iOS and Android directories you can add them to the gitignore of your project and generate them on demand):
+
+```sh
+# yarn
+yarn prebuid
+
+# npm
+npm run prebuild
+```
+
 That's it, you now have Indy SDK configured for your iOS and Android project. If you're using this plugin with [Aries Framework JavaScript](https://github.com/hyperledger/aries-framework-javascript) you will still need to follow the other setup steps, but you can skip the [Installation](https://aries.js.org/guides/getting-started/installation/react-native) for React Native.
 
+
+## Test if everything works
+
+Add the `indy-sdk-react-native` to your project:
+
+```sh
+# yarn
+yarn add indy-sdk-react-native
+
+# npm
+npm install -s indy-sdk-react-native
+```
+
+Replace your `app.js` with the following:
+
+```javascript
+import { Button, StyleSheet, View } from "react-native";
+import Indy from "indy-sdk-react-native";
+
+export default function app() {
+  const testIndy = () => {
+    Indy.createWallet({ id: "sample-id" }, { key: "sample-key" })
+      .then(() => console.log("Success!"))
+      .catch((e) => console.error(`An error occurred! ${e}`));
+  };
+
+  return (
+    <View style={styles.container}>
+      <Button onPress={testIndy} title="test indy" />
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    backgroundColor: "#fff",
+    alignItems: "center",
+    justifyContent: "center",
+  },
+});
+```
+
+
 ## Contributing
 
 Is there something you'd like to fix or add? Great, we love community