[css-align] Fix double close-paren.

Author: dbaron

css-align/Overview.bs

@@ -359,7 +359,7 @@ Baseline Alignment: the ''baseline'' keyword and ''first''/''last'' modifiers</h
 	<dfn export>Baseline alignment</dfn> is a form of positional alignment
 	that aligns multiple <a>alignment subjects</a>
 	within a <a>shared alignment context</a>
-	(such as cells within a row))
+	(such as cells within a row)
 	by matching up their <a>alignment baselines</a>.
 	If the position of the <a>alignment subjects</a> within a <a>baseline-sharing group</a>
 	is not fully constrained by <a>baseline alignment</a>