add env 'DOCKER_VOLUME_STORAGE' for volume path customization

examples/n8n/docker-compose.yml

@@ -13,7 +13,7 @@ services:
       - MARIADB_PASSWORD
       - MARIADB_MYSQL_LOCALHOST_USER=true
     volumes:
-      - /mnt/docker-volumes/n8n/database:/var/lib/mysql
+      - ${DOCKER_VOLUME_STORAGE:-/mnt/docker-volumes}/n8n/database:/var/lib/mysql
     healthcheck:
       test: "/usr/bin/mysql --user=${MARIADB_USER} --password=${MARIADB_PASSWORD} --execute 'SELECT 1;'"
       interval: 10s
@@ -36,7 +36,7 @@ services:
     links:
       - n8n-db
     volumes:
-      - /mnt/docker-volumes/n8n/storage:/home/node/.n8n
+      - ${DOCKER_VOLUME_STORAGE:-/mnt/docker-volumes}/n8n/storage:/home/node/.n8n
     command: n8n start --tunnel
     depends_on:
       n8n-db: