Finalize replace drafts.csswg.org -> w3c.github.io/csswg-drafts URL (#17802)
Finalize replace drafts.csswg.org -> w3c.github.io/csswg-drafts URL (#17802)

* Finalize replace drafts.csswg.org -> w3c.github.io/csswg-drafts URL

* let -> const
mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data