Enable menu length detection for the header#113

Lorenza 3.1.4 had the option to enable menu length detection for the header. This would switch the menu style to the Menu icon if the menu exceeded the width of the container. In Lorenza 5.0.1, the menu style on desktop does eventually switch to the Menu icon after the screen size becomes small enough, but having the above option previously available will help to prevent stacking of the navigation links from happening at all