[Feedback]Update Next.js tutorial to use new UI components

[LittleSurimi]

Page: /start/getting-started/data-model/q/integration/[integration]

Feedback:

The code for pages/index.js is outdated. the component 'AmplifyAuthenticator' has been replaced https://aws.amazon.com/blogs/mobile/amplify-uis-new-authenticator-component-makes-it-easy-to-add-customizable-login-pages-to-your-react-angular-or-vue-app/