Update react-native.md (#2068)

* Update react-native.md

Expo Demo repo had been deleted and was a broken link.

* Update sdk/quickstart/react-native.md

Co-authored-by: Alexandra Carrillo <[email protected]>

* Update sdk/quickstart/react-native.md

Co-authored-by: Alexandra Carrillo <[email protected]>

* Update react-native.md

---------

Co-authored-by: Alexandra Carrillo <[email protected]>

Author: RobItu

sdk/quickstart/react-native.md

@@ -203,9 +203,6 @@ function App() {
 }
 ```
 
-## Examples
+## Example
 
-See the following examples on GitHub for more information:
-
-- [React Native demo](https://github.com/MetaMask/metamask-sdk/tree/main/packages/examples/reactNativeDemo)
-- [Expo demo](https://github.com/MetaMask/metamask-sdk/tree/main/packages/examples/expo-demo)
+See the [React Native demo](https://github.com/MetaMask/metamask-sdk/tree/main/packages/examples/reactNativeDemo) on GitHub for more information.