[css-ui-3] calls itself Working Draft

[dansoper]

https://www.w3.org/TR/2018/REC-css-ui-3-20180621/#intro contains the words “This Working Draft incorporates...” but it is not a Working Draft. Perhaps this should be added to the list of errata?

[frivoal]

Good point. Fixed for the editor's draft (0d7f01e). @svgeesus is this something you can fix in place in the REC?

[svgeesus]

No, it can't be fixed in place but it can be noted in the errata.

[svgeesus]

Erratum added