themes_addon.dart

  @override
  Widget build(BuildContext context) {
    final lightTheme =
        WidgetbookTheme(name: 'Light theme', data: ThemeData.light());

    final darkTheme =
        WidgetbookTheme(name: 'Dark theme', data: ThemeData.dark());

    return Widgetbook.material(addons: [
      DeviceFrameAddon(
        devices: [
          Devices.ios.iPhone13Mini,
          Devices.ios.iPhone13ProMax,
        ],
        initialDevice: Devices.ios.iPhone13ProMax,
      ),
      MaterialThemeAddon(
          themes: [lightTheme, darkTheme], initialTheme: lightTheme)
    ], directories: []
}