enhancement: Add the position where you started to slide to the returned events

[Arturo Rosas]

Sometimes you need to know where the user started to swipe (and where have they finished it), for example, to display a menu if they swipe from the left half of the screen of their device.
It would be great if this data was added to the event that is passed to the functions, in order to use it.

[John Doherty]

Thank you for the suggestion @AEROGU. I added this feature in a more standards compliant way using event.detail property:

document.addEventListener('swiped-left', function(e) {
  console.log(e.target); // element that was swiped
  console.log(e.detail); // event data { dir: 'left', xStart: 196, xEnd: 230, yStart: 196, yEnd: 4 }
});