A convenience utility for firing a synthesized event.
Uses the CustomEvent constructor, which requires polyfill (provided by polyfill.io) in IE.
The function takes three arguments:
- target: An HTMLElement, which will be used to dispatch the event and determines which event listeners will be invoked;
- type: A string representing the name of the dispatched event;
- detail: An optional value, of any type, which is an event-dependent value associated with the event.