I don't think that is going to work. The only items I can add to an SSRS project are reports, data sources and datasets. I can't even create a folder.
One way for you to proceed is to add a Database project to your solution and put the procs in there.
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.