i.e. the console lets you edit the local copies of the overlay, which is created in target/webinf
by the jetty:run plugin.
ideally we'd be smart enough to auto-detect that the file name is within "target/webinf" (maybe even just within target) and so guess it might come from one of the available maven war overlays - then try deduce where it might be on disk...
typically folks will only have one or two war overlays in effect, so it shouldn't require too much hunting around (though it might be tricky finding out where the source of those overlays actually is