feat: add Docker configuration and deployment files

- Add Dockerfile for containerizing the Go application
- Add docker-compose.yml for local development environment
- Include PostgreSQL database service configuration
- Configure networking and environment variables
- Set up proper port mapping and service dependencies
- Enable easy local development and deployment

docker-compose.yml

@@ -0,0 +1,23 @@
+networks:
+  idp:
+    name: idp
+    external: false
+
+services:
+  api:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    ports:
+      - "8000:8000"
+    networks:
+      - idp
+    environment:
+      - DB_HOST=db
+      - DB_PORT=5432
+      - DB_USER=postgres
+      - DB_PASSWORD=postgres
+      - DB_NAME=idp
+      - DB_SSLMODE=disable
+      - JWT_ISSUER=idp
+      - JWT_SECRET=jlW8mwXuBs+kKibdiS6CKevNdpvAbYNTN+Fu8B3T7Jk=