assets-meshes/4thunknowns-creatures: init at 1.0
Add 4thunknowns-creatures, that I packaged some month ago, before it end up being stashed forever.
Also add it to the graphics-overhaul list (note that I had some issue installing it, and it needed more change on my system. I'll add the 2.1.0 version of portmod in nixpkgs too).