Explore better ways to attach the non-structural keyboard fascia components

[jbmorley]

The left and right-most parts of the keyboard fascia are non-structural; they just fill in gaps created by the key stagger. These are difficult to attach as they need to be mounted to the key mounting plate prior to attaching the PCB. It might be better to add some aligned holes in the PCB so these can be added after everything else has been assembled. Perhaps broaching nuts could be used here too.