Provide instructions to deploy the application using Docker containers

Adds DEPLOY.md with instructions for Docker deployment and removes init.sql mount from docker-compose.yml.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 91318273-c764-4fd4-be04-bdc12c38af32
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/0715008c-7244-40f4-befc-26c014852236/142044c4-d937-4abb-ae50-83d9764cfb4d.jpg

docker-compose.yml

@@ -13,7 +13,6 @@ services:
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-RegisFlow2024!PostgreSQL}
     volumes:
       - postgres_data:/var/lib/postgresql/data
-      - ./init.sql:/docker-entrypoint-initdb.d/init.sql:ro
     ports:
       - "5433:5432"
     restart: unless-stopped