build: docker-compose에 certbot 볼륨 마운트 추가

#136

docker-compose.yml

@@ -28,6 +28,7 @@ services:
       - "443:443"
     volumes:
       - ./client/dist:/usr/share/nginx/html
+      - ./certbot/www:/var/www/certbot
       - /etc/letsencrypt:/etc/letsencrypt:ro
     depends_on:
       - frontend