feat(geojsontiler): add interior rings support

[ctriquet-cs]

That PR addresses issue #64 by adding to geojsontiler support for interior rings.

[LorenzoMarnat]

Hello, thank you for implementing interior rings support! It's a huge enhancement for GeoJSON support.

I've tested it and it works really well:
Before:

After:

Just one small modification and we are good

[LorenzoMarnat]

Those 3 lines (36-37-38) need one less tab (or else it is not applicated to multi_geom case). Also, we need to subtract height to interior rings too

            if is_roof:
                for coord in exterior_ring:
                    coord[2] -= self.height

Should be (outside of the above else scope)

        if is_roof:
            for coord in exterior_ring:
                coord[2] -= self.height
            for interior_ring in interior_rings:
                for coord in interior_ring:
                    coord[2] -= self.height

[ctriquet-cs]

Thanks for your feedback. We applied the changes.

[LorenzoMarnat]

Perfect, thank you!