Is there a reason that MapBox doesn't zoom to France or United States when you type them in the search box?(fuuuuuuudge???!!!!)
https://www.mapbox.com/mapbox.js/example/v1.0.0/geocoding-auto/ (there is jsfiddle in the buttom of that page to test and change)
Check the documentation for L.mapbox.geocoderControl. The demo code from Mapbox in the link you listed above has the intent of just showing you how to search mapbox.places with autocomplete on.
From the documentation you will need to set a callback using geocoderControl.on(event, callback) and autoselect.
