export const metadata: Metadata = {
  title: 'Home',
  description: 'Welcome to Next.js',
}
Migrating _document.js and _app.js
If you have an existing _app or _document file, you can copy the contents (e.g. global styles) to the root layout (app/layout.tsx). Styles in app/layout.tsx will not apply to pages/*. You should keep _app/_document while migrating to prevent your pages/* routes from breaking. Once fully migrated, you can then safely delete them.
If you are using any React Context providers, they will need to be moved to a Client Component.
Migrating the getLayout() pattern to Layouts (Optional)
Next.js recommended adding a property to Page components to achieve per-page layouts in the pages directory. This pattern can be replaced with native support for nested layouts in the app directory.