Function torus

torus(hex: string): Shape
Returns a torus (donut) Shape in the specified color.
- Inner radius: 0.15 (ring is 0.3 thick)
- Total radius: 0.5 (from the centre of the hole to "outside")
- Center: Floating at (0.5, 0.5, 0.5)
Parameters
- hex: string
  hex color code
Returns Shape