Rant and a FYI to anyone who makes a gamemode.
Originally, if you have files such as models and textures that you wanted to be downloaded from the server to the client, you would put them in the gamemode/PostNukeRP/content folder for example. Any rate, here is the quote from thier site. sums it up. Makes it a bit more interesting organizing your stuff.
Gamemode content such as maps, models and sounds should be placed in the root garrysmod folder. Or if you're making a workshop addon - in the root folder.
In previous versions of Garry's Mod you would be able to put this content in a gamemodes/<gamemode>/content folder. This method was removed in Garry's Mod 13 to reduce load-times by decreasing the number of search paths.