Rokenbok Quarry Ramp

This is a replacement ramp for the Rokenbok quarry.

### Untested
The design has not been tested against real parts, only being replicated by taking measurements. The mostly hollow bottom of the part was not fully replicated, and instead was left flat. This will cause additional weight compared to the original.

### Slicing Warning
Please be aware that ramp quality can be massively impacted by layer height stair stepping, as the top surface has a very shallow angle. It may be desirable to print on its side to ensure a smoother driving surface. Unfortunately a small protrusion will cause printing on the side to require support material, and may degrade the surface quality of that side. It may be desirable to omit the small protrusion before printing this way. These protrusions serve to hold the quarry closed in storage.