Automatically add workshop files to search path

[BenLubar]

Is your feature request related to a problem? Please describe.
This is just a quick feature idea I had.

Is your feature request related to a specific game? Please specify.
Any Source Engine game with Steam Workshop support.

Describe the solution you'd like
The auto-detect for installed games should add a wildcard directory for the workshop folder for the applicable game.

Additional context
For example, AS:RD is located at D:\Program Files\Steam\steamapps\common\Alien Swarm Reactive Drop\reactivedrop on my computer and the VPK files from the workshop are located in subfolders of D:\Program Files\Steam\steamapps\workshop\content\563560