[css-align-3][editorial] Fixed Bikeshed error

Author: SebastianZ

css-align-3/Overview.bs

@@ -2681,7 +2681,7 @@ Changes</h2>
 			(<a href="https://github.com/w3c/csswg-drafts/issues/1318">Issue 1318</a>)
 		<li>Clamped baselines of scrollable boxes to the border edge, rather than margin edge.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/766">Issue 766</a>)
-		<li>Updated the flex container gap definition to use 'gutter'. (<a href="https://github.com/w3c/csswg-drafts/issues/12084">Issue 12084</a>)
+		<li>Updated the flex container gap definition to use [=gutter=]. (<a href="https://github.com/w3c/csswg-drafts/issues/12084">Issue 12084</a>)
 	</ul>
 
 <h2 id="privacy">