Fix syntax of boolean attributes

[Jym77]

HTML boolean attributes are set simply by their presence and explicit ="true" is bad…

Closes issue(s):

• closes 'audio or video has no audio that plays automatically' failed examples aren't failures #1160

Need for Final Call:
This will require a 1 week Final Call (changing most examples)

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[Jym77]

Final Call ends on February 20.

[adilsofficial]

Applicability section for these rules should be updated:

• an autoplay attribute that is equal to true, and
  autoplay attribute is not explicitly required to be equal to true as already fixed in this PR. Presence of this attribute in audio or <video> tag is enough for being true.
• both paused and muted attributes equal to false, and
  The default value of both paused and muted attributes is false. If not presented it will be considered as false.
  These sentences should be updated/fixed according to the examples fixed in this PR.

[Jym77]

Applicability section for these rules should be updated:

• an autoplay attribute that is equal to true, and
  autoplay attribute is not explicitly required to be equal to true as already fixed in this PR. Presence of this attribute in audio or <video> tag is enough for being true.
• both paused and muted attributes equal to false, and
  The default value of both paused and muted attributes is false. If not presented it will be considered as false.
  These sentences should be updated/fixed according to the examples fixed in this PR.

Very good catch. Thank you.

I've updated the applicabilities to use a correct formulation (the value of the attribute can be true in different ways: autoplay, autoplay="", autoplay="autoplay", autoplay="AUTOplay", …: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#boolean-attribute).

[dd8]

Looks good. I checked the failure examples - these autoplay in Edge/IE and in Chrome/FF if autoplay is allowed

[Jym77]

Final Call has ended. Merging.