Scene constructor documentation is confusing/inconsistent

[eonarheim]

Steps to Reproduce

https://codesandbox.io/s/excaliburjs-reproduction-01-pezj9

import * as ex from 'excalibur'

const game = new ex.Engine({
  width: 800,
  height: 600,
  displayMode: ex.DisplayMode.FullScreen,
  pointerScope: ex.Input.PointerScope.Document,
})

const Scene1 = new ex.Scene()
const label = new ex.Label('Hello', 10, 10, '48px Arial')

Scene1.add(label)

game.addScene('Scene1', Scene1)
game.goToScene('Scene1')
game.start()

Expected Result

The typings for new ex.Scene indicate that it requires an Engine object to be passed in, yet it actually does not. Why is this? I see that the argument is labeled in the Typescript idiom which indicates an unused variable (leading underscore).

Actual Result

Engine is not actually required

Environment

• operating system: n/a
• Excalibur versions: master

Current Workaround

Use ex.Scene with or without passing an Engine argument

Suggested fix

Either update the documentation to disambiguate proper usage, or correct the typing on ex.Scene