Prepare upright z-actuator mount

The upright z-actuator mount needs four nuts embedded. This is called out in words on the 'mount optics' page (step 2). The mounting spacer should be prepared with the nuts inserted along with the main body and the stand.

The 'prepare main body' step 3 calls for three nuts in the illumination platform for upright, but only shows two. The third nut also needs to show in the transparent renders during the mount the illumination sequence for Upright.