A note regarding the feature `startAt` of `TimerEvent `
When an event gets added it should be either scaled by clock `timeScale`
as well or not scaled at all - depending on the feature purpose.
```javascript
// preUpdate loop
event.elapsed = event.startAt * event.timeScale
```
In my understanding it should not be influenced by `timeScale` at all.
As a developer I would use the feature of `startAt` to specify the exact
offset for my event.
In case I have looped `Timer` for one second and want to start the first
loop in the middle, I would set the `startAt` to half a second. And
scaling is applied during the timer run time as a factor of speed it
elapses.
