Addons models

Hi everyone,

I’m the author of the Sp4s12’s Content addon. unfortunatly, it was made with a structure in which all my models are spread into the spawn tree of the GMod13 menu.
This is an image of what i’m talking about :
http://img15.hostingpics.net/pics/524922Sanstitre.png

in red, all my models which are spread into the menu…

actually, i was thinking that all my models would be placed in a Sp4s12’s Content folder into the addon folder (in green on my pic).
like Addons/Sp4s12’s contents/…

so… is it a bug of GMod13 or is there a way to create a spawnlist which could be accepted by Workshopper ?

thank you !