New Type TextPronunciation

[RichardWallis]

Implements proposal in issue (#2108 - Schema for specifying how to pronounce text) - see issue for discussion.

Adds new Type TextPronunciation and associated properties phoneticText, speechToTextMarkup and textValue.

Defined as a subtype of Text it could be used on any property that currently expects a Text value. Most common usage will probably be as additional values for name properties.

Examples include:

{
  "@context": "http://schema.org/",
  "@type": "City",
  "name": {
    "@type": "TextPronunciation",
    "inLanguage": "en-US",
    "textValue": "Worcester",
    "speechToTextMarkup": "IPA",
    "phoneticText": "/ˈwʊstɚ/"
  }

{
  "@context": "http://schema.org/",
  "@type": "RadioStation",
  "name": ["WKRP",
      {
        "@type": "TextPronunciation",
        "textValue": "WKRP",
        "speechToTextMarkup": "SSML",
        "phoneticText": "<speak><say-as interpret-as=\"characters\">WKRP</say-as>"
      }
  ]
}

[RichardWallis]

Snippet for Pending section of releases.html:

<li id="2108"><a href="https://github.com/schemaorg/schemaorg/issues/2108">Issue #2108</a>:
(implemented in <a href="https://github.com/schemaorg/schemaorg/pull/2352">PR #2352</a>):
Introduced new pending type <a href="/TextPronunciation">TextPronunciation</a> enabling phonetic markup of text values.
</li>

[danbri]

thanks for the fix @RichardWallis :)