Fix readme

README_CN.md

@@ -158,6 +158,11 @@ has, err := engine.Table(&user).Where("name = ?", name).Cols("id").Get(&id)
 has, err := engine.SQL("select id from user").Get(&id)
 // SELECT id FROM user WHERE name = ?
 
+var id int64
+var name string
+has, err := engine.Table(&user).Cols("id", "name").Get(&id, &name)
+// SELECT id, name FROM user LIMIT 1
+
 var valuesMap = make(map[string]string)
 has, err := engine.Table(&user).Where("id = ?", id).Get(&valuesMap)
 // SELECT * FROM user WHERE id = ?