[ttml2] Permit `ttm:role` attribute in `ttm:desc` elements (#1247)

nigelmegitt has just created a new issue for https://github.com/w3c/ttml2:

== Permit `ttm:role` attribute in `ttm:desc` elements ==
I've seen real world usage of the `ttm:role` attribute on `ttm:desc` elements, used to describe the purpose/type of description. Suggest in ยง14.2.2 adding [Metadata Items](https://www.w3.org/TR/ttml2/#element-vocab-type-metadata-items) alongside Content. It could also be useful on Data elements.

Please view or discuss this issue at https://github.com/w3c/ttml2/issues/1247 using your GitHub account


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Received on Wednesday, 14 September 2022 17:16:48 UTC