ability to specify music directory at runtime in settings pane

I built this app, saw the message in the console that the app was listening on http, fired up a web browser, then tried to add my music.

I clicked into "Library" and "Settings" and saw no way of telling groovebasin how to find my music.

There should be a watched directory user preference available in the Settings UI that shows the filesystem of the machine that groovebasin is running on that allows users to add a directory to watch. As a stopgap, documentation ought to be added that makes it clear that users need to edit the config.js file that is generated on first start.