fix index

playground/src/app.js

 }
 
 export function start() {
-  Navigation.onAppLaunched('onAppLaunched', () => {
+  Navigation.onAppLaunched(() => {
     Navigation.registerContainer(`com.example.WelcomeScreen`, () => WelcomeScreen);
     Navigation.startApp({
       container: {

src/index.js

-import * as Navigation from './Navigation';
+import Navigation from './Navigation';
 
 module.exports = Navigation;
 module.exports.default = Navigation;