Need documented way to import supervoxel->label affinities

[pgunn]

I believe the current documentation doesn't cover this (although there are hints that some kind of an hdf5 file is involved) and it suggests (which may be dated) that this is only available for dedicated-server installs of webknossos; at the Berlin conference based on conversations, I got the impression that there's now a more widely available way to import SV->Label affinity maps into the platform, including for the centrally-hosted version.

Docs on how to do this would be great.