make command "docker plugin inspect" complete

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

docs/reference/commandline/plugin_inspect.md

@@ -12,7 +12,7 @@ parent = "smn_cli"
 # plugin inspect (experimental)
 
 ```markdown
-Usage:  docker plugin inspect PLUGIN
+Usage:  docker plugin inspect [OPTIONS] PLUGIN [PLUGIN...]
 
 Inspect a plugin