Add missing quote, per Dave Page.

doc/src/sgml/docguide.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.55 2005/04/09 03:52:43 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.56 2005/05/13 16:48:14 tgl Exp $ -->
 
 <appendix id="docguide">
  <title>Documentation</title>
@@ -417,7 +417,7 @@ perl -pi -e 's/iso-(.*).gml/ISO\1/g' docbook.cat
      <filename>/usr/local/share/sgml/catalog</filename> can also be
      made:
 <programlisting>
-CATALOG "docbook-dsssl-1.<replaceable>xx</>/catalog
+CATALOG "docbook-dsssl-1.<replaceable>xx</>/catalog"
 </programlisting>
      Because stylesheets change rather often, and it's sometimes
      beneficial to try out alternative versions,