This patch fixes the partitioning synopsis in the Parameters section in
the CREATE FOREIGN TABLE documentation. Follow-up for commit
ce21a36cf.
Back-patch to v11 where default partition was introduced.
Reviewed by Amit Langote and Robert Haas.
Discussion: https://postgr.es/m/CAPmGK17U5jEqVZuo3r38wB0VFWomEtJCBGn_h92HQzQ2sP-49Q%40mail.gmail.com