v2.2.1 - Mobile UI, License & Docs Polish

📱 Mobile-Friendly Viewer

• Responsive Layout: Sidebar now hides on mobile when a chat is selected.
• Back Button: Added a back button in the chat header to return to the chat list on mobile.

📝 Documentation & License

• GPL-3.0 License: Added official LICENSE file.
• Docs Cleanup: Updated README.md with requested changes.

🚀 Deployment

docker pull drumsergio/telegram-backup-automation:2.2.1
docker pull drumsergio/telegram-backup-automation:latest