Add compat data for @font-face format descriptor (#5975)
Add compat data for @font-face format descriptor (#5975)

* Add compat data for @font-face format descriptor

In the 20 September 2018 draft of CSS Fonts Module Level 4, the src parsing rules were updated to allow keywords in format() hints.

https://www.w3.org/TR/2018/WD-css-fonts-4-20180920/#font-format-values
https://www.w3.org/TR/2018/WD-css-fonts-4-20180920/#changes-2018-04-10

* Add presumed compat data for @font-face format descriptor

This data could not be directly tested, but is inferred by corresponding browser/engine combinations.
chrisdavidmills/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data