>Or, as @elextr suggested, have a look at the Addons plugin. Adding a new shortcut there to show/hide the menu bar is probably no big deal, is less work than creating a whole new plugin with all boilerplate and has good chances to be merged.
I don't like the idea that `Toggle menu bar` is part of an other plugin. I think that it is user-friendly when users see directly in the name of the plugin what the plugin is doing. And I think that mixed subjects in a name are not a good idea.