Distance to surface for ellipsoids #163
Description
Feature description
I would like to get the distance to the surface of the shape for ellispoids
Proposed solution
add a distance_to_surface method for ellipsoids
Additional context
The distance_to_surface method was added for many 2D shapes a while ago in #141 (#136 #137 #140 are related issues), but that PR didn't handle any 3D shapes. There are analytical equations for the surface of an ellipsoid, so it should be pretty quick to add this.