Release v1.0.4

✨ Added new /hello command and improved decryption error handling


- 🚀 Added a new /hello command to greet users.
- 🛠 Refactored decrypt_message function to avoid nested definitions.
- 🐛 Fixed `UnboundLocalError` by initializing the `decrypted` variable.
- 📄 Updated /start and /help messages to include the new /hello command.
- 🔒 Enhanced decryption flow with improved error handling and MarkdownV2 escaping.
new PyPi v.1.0.4