Log Message:
-----------
Add reference to the NewbieDoc Docbook Guide.
Modified Files:
--------------
pgsql/doc/src/sgml:
docguide.sgml (r1.51 -> r1.52)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/docguide.sgml.diff?r1=1.51&r2=1.52)