[css-pseudo] Add text-combine-upright to ::marker per https://lists.w3.org/Archives/Public/www-style/2015Apr/0143.html

Author: fantasai

css-pseudo/Overview.bs

@@ -671,6 +671,7 @@ List Markers: the ''::marker'' pseudo-element</h3>
   <ul>
     <li>all font properties (see [[CSS3-FONTS]])
     <li>the 'color' property (see [[CSS3COLOR]])
+    <li>the 'text-combine-upright' property (see [[CSS3-WRITING-MODES]])
   </ul>
 
   <p class="note">