Suggestion: equi-volume layering based on curvature

[TimVanMourik]

The current implementation of equivolume layering is based on a volume computation based on the size of faces on the white patter and pial. A different way of computing the same thing is presented in Kleinnijenhuis 2015, see supplemental methods.

I have no idea which method is better or worse and if there even exists such a thing, but it could be nice to implement it as an alternative. The Matlab code is available here. I'll try and have a look to see if I can Pythonify it at some point. But feel free to take it up if you'd like 👍