Adds support for Spanish, Dutch, Russian, and Chinese to the language selection menu. This includes adding the necessary translation strings and updating the app customization page to display these new language options.
- Expanded the localization support by adding new languages: Chinese (zh), Russian (ru), Dutch (nl), and Spanish (es).
- Updated the localization files and the AppLocalizations class to include the new languages, ensuring a broader reach for international users.
- Enhanced the isSupported method to recognize the newly added languages, improving the app's adaptability to diverse user preferences.
