[css-counter-styles-3] Add cjk-decimal fallback to cjk-earthly-branch/cjk-heavenly-stem w3c#8975 (w3c#9597)

Author: fantasai

css-counter-styles-3/Overview.bs

@@ -1856,13 +1856,15 @@ Fixed: ''cjk-earthly-branch'', ''cjk-heavenly-stem''</h3>
 		symbols: "\5B50" "\4E11" "\5BC5" "\536F" "\8FB0" "\5DF3" "\5348" "\672A" "\7533" "\9149" "\620C" "\4EA5";
 		/* 子 丑 寅 卯 辰 巳 午 未 申 酉 戌 亥 */
 		suffix: "、";
+		fallback: cjk-decimal;
 	}
 
 	@counter-style cjk-heavenly-stem {
 		system: fixed;
 		symbols: "\7532" "\4E59" "\4E19" "\4E01" "\620A" "\5DF1" "\5E9A" "\8F9B" "\58EC" "\7678";
 		/* 甲 乙 丙 丁 戊 己 庚 辛 壬 癸 */
 		suffix: "、";
+		fallback: cjk-decimal;
 	}
 	</bdo></pre>
 
@@ -2648,6 +2650,10 @@ Changes since the July 2021 Candidate Recommendation</h3>
 
 	Significant changes since the <a href="https://www.w3.org/TR/2021/CR-css-counter-styles-3-20210727/">July 27 2021 Candidate Recommendation</a>:
 
+	* Added ''fallback: cjk-decimal'' descriptor
+		to ''cjk-earthly-branch'' and ''cjk-heavenly-stem''.
+		(<a href="https://github.com/w3c/csswg-drafts/issues/8975">Issue 8975</a>)
+
 	* Restored the <css>fallback: cjk-decimal</css> descriptor
 		to the Korean styles
 		which was accidentally dropped in