How to add 'src' folder to solution root

Question

This will sound like a dumb question, but Visual Studio doesn't seem to allow me to do this simple organization that I see all the time on github.

I start with a new blank solution.

Then I want to add the "src" folder, which will contain multi-project projects. If I right-click and select "Add Folder", VS will add a virtual folder, not the actual folder.

If I use Windows Explorer to create a new folder in the right place, VS ignores it and does not allow me to "Add to solution"

If I add a project, it adds the project to the root directory, and not to the desired folder.

So how do I add this folder?