Refactor Docker setup for environment flexibility and dev support

Moved environment variables to .env.template for better management and updated docker-compose files to use them. Added separate docker-compose.dev.yml for development, a Makefile for streamlined commands, and split backend Dockerfile into development and production stages. Updated .gitignore to include new changes.

.env.template

@@ -0,0 +1,25 @@
+# Common settings
+PROJECT_NAME=EventSpace
+VERSION=1.0.0
+
+# Database settings
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=postgres
+POSTGRES_DB=eventspace
+POSTGRES_HOST=db
+POSTGRES_PORT=5432
+DATABASE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${POSTGRES_HOST}:${POSTGRES_PORT}/${POSTGRES_DB}
+
+# Backend settings
+BACKEND_PORT=8000
+SECRET_KEY=your_secret_key_here
+ENVIRONMENT=development
+DEBUG=true
+BACKEND_CORS_ORIGINS=["http://localhost:3000"]
+FIRST_SUPERUSER_EMAIL=admin@example.com
+FIRST_SUPERUSER_PASSWORD=admin123
+
+# Frontend settings
+FRONTEND_PORT=3000
+NEXT_PUBLIC_API_URL=http://localhost:8000
+NODE_ENV=development