This is used for loading all the textures of darkrp that is using csgo textures. First of all you need winrar for this
TUTORIAL: so you go to this page download the css content with winrar. now you need to go to the Folder were you have gmod installed.
C:\Program Files (x86)\Steam\steamapps\common\GarrysMod\garrysmod\addons
You have to extract what is in the WinRAR folder to the other folder (this one over here ⬆️). Now when everything is installed there. Restart the garry's mod and you will have all the textures / sounds.
you need winrar for this. i hope its helpful for you!
http://files.fragboss.com/CSS Game Content.zip
All this is allowed because your not installing the game just the textures so if you have allready the game you dont need this. its just for the people that dosent have csgo. if you dont have it you can do this tutorial.