refactor(env): remove relational database configuration from example file

Author: yokoberek

.env.example

@@ -5,13 +5,6 @@ DEBUG=True
 ALLOWED_HOSTS=127.0.0.1,localhost
 CSRF_TRUSTED_ORIGINS=http://localhost
 
-# RELATIONAL DATABASE
-POSTGRES_HOST=your-db-host
-POSTGRES_PORT=your-db-port
-POSTGRES_USERNAME=your-db-username
-POSTGRES_PASSWORD=your-db-password
-POSTGRES_DATABASE=your-db-name
-
 # CACHING DATABASE
 REDIS_HOST=your-db-host
 REDIS_PORT=your-db-port