I'm just starting with your plugin, very useful, thanks!
One thing, though.
I already have too many items in the top level of the admin menu.
And actually your plugin only needs one link, as the sub-menu Readme&Licence could have its content in the very settings page.
I know that, for marketing purposes, it's much better to be at the first level and have your custom icon and all.
But IMHO the first level should be reserved to menus with lots of options for populating the sub-menu.