Update expo config plugin to use ReactNativeDelegate in SDK 53

[kadikraman]

Summary

While upgrading the React Conf app to SDK 53 today, I encountered the following error:

Following this change, config plugins should be added via the ReactNativeDelegate.

Test Plan

Verified on the React Conf app.

• yarn build
• copy the new dist folder the React Conf app (this is the branch I used)
• npx expo run:ios

What's required for testing (prerequisites)?

Checkout this on the React Conf app repo.

What are the steps to test it (after prerequisites)?

• yarn in the React Conf project
• yarn build in this project
• copy the new dist folder to the node_modules (or use yalc to publish it locally)
• npx expo run:ios

Compatibility

OS	Implemented
iOS	✅
Android	❌

Checklist

• I have tested this on a device and a simulator
• I added the documentation in README.md
• I added a sample use of the API in the example project (example/App.tsx)

[zoontek]

Thanks @kadikraman ! Releasing it just after.

[zoontek]

And here it is: https://github.com/zoontek/react-native-bootsplash/releases/tag/6.3.6