[text-decor-3] Correction to text shadows description

Regarding this section on text shadows:

http://dev.w3.org/csswg/css-text-decor-3/#text-shadow-property

It says:

"Values are interpreted as for 'box-shadow' [CSS3BG]. (But note that spread
values are not allowed.)"

The box-shadow section of the spec that this links to explains that the
box-shadow property also accepts an optional "inset" keyword. This keyword
is not allowed for the text-shadow property, so the note in the parentheses
should be updated to say:

"(But note that spread values and the inset keyword are not allowed.)"

Please correct this. Thank you!

Louis