[css-ruby-1] Add zh-Hanb to 30% font-size rule w3c#775

Author: fantasai

css-ruby-1/Overview.bs

@@ -2089,7 +2089,8 @@ Appendix A: Sample Style Sheets</h2>
 
 		rtc, :not(rtc) > rt {
 			font-size: 50%; }
-		rtc:lang(zh-TW), :not(rtc) > rt:lang(zh-TW) {
+		rtc:lang(zh-TW), :not(rtc) > rt:lang(zh-TW),
+		rtc:lang(zh-Hanb), :not(rtc) > rt:lang(zh-Hanb), {
 			font-size: 30%; }               /* bopomofo */
 	</pre>
 
@@ -2263,6 +2264,7 @@ Changes since the 2 December 2021 WD</h3>
 	<ul>
 		<li>Made the computed-value adjustement of 'writing-mode' on [=inter-character annotations=]
 			apply to the [=ruby annotation box=] rather than the [=ruby annotation container box=].
+		<li>Added <code>zh-Hant</code> to rule applying ''font-size: 30%'' to [=ruby annotations=] in HTML.
 	</ul>
 
 <h3 id="changes-20200429">