[css-gcpm] fixed unescaped angle bracket in propdef

Author: dauwhe

css-gcpm/Overview.src.html

@@ -59,7 +59,7 @@ <h4 id="setting-named-strings-the-string-set-pro">
 ''content-list'' expands to one or more of the following values, in any order. 
 
 <pre class="prod">
-	<dfn id="content-list">content-list</dfn> = [ &lt;string> | &lt;counter()> | &lt;counters()> | &lt;content()> | attr(<identifier>) ]+
+	<dfn id="content-list">content-list</dfn> = [ &lt;string> | &lt;counter()> | &lt;counters()> | &lt;content()> | attr(&lt;identifier>) ]+
 </pre>