pgsql: Doc: sync CREATE GROUP syntax synopsis with CREATE ROLE.

Doc: sync CREATE GROUP syntax synopsis with CREATE ROLE.

CREATE GROUP is an exact alias for CREATE ROLE, and CREATE USER is
almost an exact alias, as can easily be confirmed by checking the
code.  So the man page syntax descriptions ought to match up.  The
last few additions of role options seem to have forgotten to update
create_group.sgml, though.  Fix that, and add a naggy reminder to
create_role.sgml in hopes of not forgetting again.

Discussion: https://postgr.es/m/158647836143.655.9853963229391401576@wrigleys.postgresql.org

Branch
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REL9_5_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/7b99e46742fc93e0cd8d48b0eec55eca1a7b2790

Modified Files
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doc/src/sgml/ref/create_group.sgml | 3 +++
1 file changed, 3 insertions(+)