For deletion, if the submenu has some menu items, they would all get deleted as well, this could be done by just extending /did -d to support menu.
'Adding' a menu would be done by adding a menu item to a menu item, did -a could also be extended that way.
Inserting a menu is not really a thing, but it could be scripted with addition and deletion.
Ideally, such an operation on menu would work even for the root menu, since you wouldn't be able to add a menu item to a menu item to create a new menu from the root, there could be a different syntax to do that, such as /did -a name -1 <newmenuid> <text>
