[css-fonts-4] Add missing font-variant-emoji to reset implicitly group, w3c#7832

Author: svgeesus

css-fonts-4/Overview.bs

@@ -1575,6 +1575,7 @@ Shorthand font property: the 'font' property</h3>
 				<li>'font-variant-alternates!!property'</li>
 				<li>'font-variant-caps!!property' (css3 and above)</li>
 				<li>'font-variant-east-asian!!property'</li>
+				<li>'font-variant-emoji!!property'</li>
 				<li>'font-variant-ligatures!!property'</li>
 				<li>'font-variant-numeric!!property'</li>
 				<li>'font-variant-position!!property'</li>