How do I expose a folder in my build

To make my game moddable I have exposed a few folders (as in, they appear in the Game_Data folder as local files) so that Unity will fetch models and read text files from them, enabling users to replace the files in that folder to their own liking.

As of right now I have to manually add those folders after building, because Unity deletes them.

So my questions is: How do I make unity copy specific folders directly from the Assets folder to the newly created Game_Data folder after building?

everything you put in the folder StreamingAssets, will be outside the build package, this is used for some references that will be changed after deployment or downloaded from network