[css-text] Clarify importance of writing system as well as language for lang-specific effects #2015
Description
https://www.w3.org/TR/css-text-3/#languages notes that typographic effects vary by language but should also mention writing system, and should give examples like ja-latn to emphasize that UAs need to detect script tags. See https://twitter.com/little_potato/status/935608512297820160