pgsql: doc: clarify which table creation is used for inheritance part.

doc:  clarify which table creation is used for inheritance part.

Previously people might assume that the partition syntax version of
CREATE TABLE is to be used for the inheritance partition table example;
mention that the non-partitioned version should be used.

Reported-by: mib@nic.at

Discussion: https://postgr.es/m/158089540905.1098.15071165437284409576@wrigleys.postgresql.org

Backpatch-through: 10

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/51a1c77bd769642670249554e48ad99698ea61fc

Modified Files
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doc/src/sgml/ddl.sgml | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)