pgsql: Re-add FAQ item 3.7 which was accidentally removed in previous

Log Message:
-----------
Re-add FAQ item 3.7 which was accidentally removed in previous commit:

<H3 id="item3.7">3.7) What computer hardware should I use?</H3>

Modified Files:
--------------
pgsql/doc:
FAQ (r1.422 -> r1.423)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/FAQ.diff?r1=1.422&amp;r2=1.423)
pgsql/doc/src/FAQ:
FAQ.html (r1.378 -> r1.379)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/FAQ.html.diff?r1=1.378&amp;r2=1.379)