Clean up .env.example by removing unused DB options

Removed commented-out PostgreSQL and MySQL configuration options from the example environment file.

Author: GitTimeraider

.env.example

@@ -9,18 +9,9 @@ DATABASE_URL=sqlite:///subscriptions.db
 
 # Option 2: PostgreSQL
 # DATABASE_URL=postgresql://subscription_tracker:subscription_tracker@postgres:5432/subscription_tracker
-# POSTGRES_DB=subscription_tracker
-# POSTGRES_USER=subscription_tracker
-# POSTGRES_PASSWORD=subscription_tracker
-# POSTGRES_PORT=5432
 
 # Option 3: MariaDB/MySQL
 # DATABASE_URL=mysql+pymysql://subscription_tracker:subscription_tracker@mariadb:3306/subscription_tracker
-# MYSQL_DATABASE=subscription_tracker
-# MYSQL_USER=subscription_tracker
-# MYSQL_PASSWORD=subscription_tracker
-# MYSQL_ROOT_PASSWORD=root_password
-# MYSQL_PORT=3306
 
 # Email Configuration (SMTP)
 MAIL_SERVER=smtp.gmail.com