Add Docker deployment and improved documentation.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 705f2157-ef97-4fbd-89e4-8c7f2ecaea90
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/7ed01c5f-a82d-405a-b728-b2e3d127c60c/aea157e5-907c-4910-b5b7-c0994e1daea0.jpg

docker-compose.yml

@@ -10,6 +10,7 @@ services:
     environment:
       - NODE_ENV=production
       - PORT=5000
+      - BASE_URL=${BASE_URL:-http://localhost:5000}
       - DATABASE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
       - REDIS_URL=redis://redis:6379
       - SESSION_SECRET=${SESSION_SECRET}