The 'routes' table is a point of confusion with new developers. By
providing a 'home' argument that sets the '/' route, we can delay the
point at which we teach developers about 'routes' until the point where
they want to have a second route.
* left -> leading (Removes an LTR bias)
* center -> title (Widget was actually centered)
* right -> actions (Removes an LTR bias, asymmetric with leading)
Fixes#2348
