[css-inline] Add math heuristic to issue per https://lists.w3.org/Archives/Public/www-style/2015Nov/0349.html

Author: fantasai

css-inline/Overview.bs

@@ -8,8 +8,7 @@
 <pre class='metadata'>
 Shortname: css-inline
 Level: 3
-Status: WD
-Date: 2016-05-24
+Status: ED
 Work Status: Revising
 Group: csswg
 TR: https://www.w3.org/TR/css-inline/
@@ -1094,7 +1093,7 @@ Appendix A: Synthesizing Baselines</h2>
 		<li>Measure the font.
 			<div class="issue">Describe in more detail.
 			Should we document which characters in which scripts are useful,
-			such as lowercase "o" to measure x-height? See https://drafts.csswg.org/css-values/#ex</div>
+			such as lowercase "o" to <a href="https://drafts.csswg.org/css-values/#ex">measure x-height</a> or the middle of the minus sign for the mathematical baseline?</div>
 
 		<li>Use a heuristic for the script.