Don't show the component navigator if there is only one component.

At the moment, you will always see the component navigator, even if there is no other component to navigate to.

It might be nice to have an option somewhere that could prevent the component navigator from showing if there was only one component.

It could be set up as an option in the playbook file (though this might tie the playbook to the UI style, so perhaps not the best idea), or handled as part of the CSS in the UI.