add bash symbol for docker network inspect

Signed-off-by: lixiaobing10051267 <li.xiaobing1@zte.com.cn>

docs/userguide/networking/work-with-networks.md

@@ -882,7 +882,7 @@ $ docker network disconnect isolated_nw container3
 ```
 
 ```bash
-docker network inspect isolated_nw
+$ docker network inspect isolated_nw
 
 [
     {