made useCapture optional

"If true, useCapture indicates that the user wishes to initiate capture. After initiating capture, all events of the specified type will be dispatched to the registered listener before being dispatched to any EventTarget beneath it in the DOM tree.
Events which are bubbling upward through the tree will not trigger a listener designated to use capture. [...]
If not specified, useCapture defaults to false."
Source: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget.addEventListener