refactor: Implement Docker, MySQL logging, and SMTP email

This commit refactors the application to run in a containerized environment using Docker and Docker Compose. It also introduces a MySQL database for logging user requests and updates the print functionality to send emails via SMTP.

Key changes:
- Added `Dockerfile` and `docker-compose.yml` for containerization.
- Integrated a MySQL database for logging user requests.
- Updated the print module to send files as email attachments via SMTP.
- Added and updated configuration files (`.env`, `.env.example`) to manage secrets and environment variables.
- Removed hardcoded credentials from version control.
- Updated `Readme.md` with new setup and execution instructions.

.env.example

@@ -0,0 +1,22 @@
+# Configuración de Telegram
+TELEGRAM_TOKEN=TU_TOKEN_NUEVO_AQUI
+
+# Webhooks de n8n (puedes agregar más aquí en el futuro)
+WEBHOOK_CONTRATO=
+WEBHOOK_PRINT=
+WEBHOOK_VACACIONES=
+
+# --- DATABASE ---
+# Usado por el servicio de la base de datos en docker-compose.yml
+MYSQL_DATABASE=vanessa_logs
+MYSQL_USER=user
+MYSQL_PASSWORD=password
+MYSQL_ROOT_PASSWORD=rootpassword
+
+# --- SMTP ---
+# Usado por el módulo de impresión para enviar correos
+SMTP_SERVER=smtp.hostinger.com
+SMTP_PORT=465
+SMTP_USER=your_email@example.com
+SMTP_PASSWORD=your_password
+SMTP_RECIPIENT=your_email@example.com