Stemi d=84mm plate

The height of the models are 4.6mm. I think the original part is 5mm, but this works for me.

I only tested with Stemi 508. I think Stemi 305 also uses the same part, so this should also work.

I needed a hole in the plate as it makes it simpler to put a flower and change the orientation with a spherical stage. I also added a plate without hole if you need that.

I print with mk3s 0.2mm quality setting.