docs: function Featherlight($content, config) {
  		if(this instanceof Featherlight) {  /* called with new */
  			this.id = Featherlight.id++;
  			this.setup($content, config);
  			this.chainCallbacks(Featherlight._callbackChain);
  		} else {
  			var fl = new Featherlight($content, config);
  			fl.open();
  			return fl;
  		}
  	}