[selectors-4][editorial] correct link to html a element not lab (color) a

Author: svgeesus

selectors-4/Overview.bs

@@ -1175,7 +1175,7 @@ Binding to the Document Tree</h4>
 
 	<div class='example'>
 		For example, in the selector ''div a::before'',
-		the ''a'' elements matched by the selector are the <a>originating elements</a>
+		the <{a}> elements matched by the selector are the <a>originating elements</a>
 		for the ''::before'' pseudo-elements attached to them.
 
 		The selector ''::first-line'' is equivalent to ''*::first-line'',