package:web v0.5.1

• Add TrustedTypes members.
• Include MDN API documentation as class and member dartdoc comments. Docs
  sourced from the [MDN Web Docs][] project; attributions and copyright
  licensing by Mozilla Contributors is licensed under [CC-BY-SA 2.5][].
• Add a constructor for each Element tag onto their respective Element
  interfaces.
• Remove external Element constructors that would result in a runtime error.
• Deprecate createAudioElement in favor of the HTMLAudioElement constructor.
  [MDN Web Docs]: https://developer.mozilla.org/en-US/docs/Web
  [CC-BY-SA 2.5]: https://creativecommons.org/licenses/by-sa/2.5/