Add :focus-visible data. (#2347)
Add :focus-visible data. (#2347)

* Add focus-visible css selector.

* Add flag name.

* Change null to false.

mdn/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,teoli2003/browser-compat-data