The folder just has to have the name of the library. The SVG can be called anything. I usually name it the same for all libraries so I can just copy and not edit the resource json file. Maybe that's lazy... But I like to claim it as being consistent 
it's less convenient if you had multiple library svg's open at once as they'd all have the same name, but I would rarely open the SVG directly anyway, let alone multiple...
Thanks for the clarification, I also changed the above 