You can currently do this.
Go to your install location for UE4 (usually C: drive) X:/Program Files/Unreal Engine/(Engine version number installed)/Samples/StarterContent/Content/Place files here or in specific folder
To utilize this when you create a new project you would create a new project > then check the “Include Starter Content” to have your files included.
You can customize this folder to your liking to include whatever content you would like. If you don’t want any of the pre-made starter content I would suggest deleting or backing up somewhere.
You may have to do this with each version number of the engine that comes out but I’ve not tested if that is the case though.
I hope this helps!