docs: link to apple docs

this is mostly to trigger a new build to run the brew stuff

Sources/hyper-focus/idle_checker.swift

@@ -25,6 +25,7 @@ class IdleChecker {
  private func systemIdleTime() -> TimeInterval {
  // the "anyInputEventType" is NOT defined in swift!
  // https://stackoverflow.com/questions/31943951/swift-and-my-idle-timer-implementation-missing-cgeventtype
+ // https://developer.apple.com/documentation/coregraphics/cgeventsource/1408790-secondssincelasteventtype
  let anyInputEventType = CGEventType(rawValue: ~0)!
 
  let idleTimeInMilliseconds = CGEventSource.secondsSinceLastEventType(CGEventSourceStateID.combinedSessionState, eventType: anyInputEventType)