Documentation gap: Perl interfaces

I just noticed that the SGML documents contain no description of the
perl5 interface (Pg.pm), nor yet any mention that there is a DBI/DBD
driver available.  Anyone looking at the "Client Interfaces" section
would think there is no Perl interface available at all :-(.

I am not sure that it's worth transcribing interfaces/perl5/README
into SGML, given that we aren't encouraging new development with that
code anyway.  But surely there should be some mention of DBI.

            regards, tom lane