pgsql: doc: Move parallel_leader_participation to its correct category

doc: Move parallel_leader_participation to its correct category

parallel_leader_participation got introduced in e5253fd, where it was
listed under RESOURCES_ASYNCHRONOUS in guc.c, but the documentation
did not reflect that and listed it with the other planner-related
options. This commit fixes this inconsistency as the parameter is
intended to be an asynchronous one.

While on it, reorganize a bit the section dedicated to asynchronous
parameters, backend_flush_after being moved first to do better in terms
of alphabetical order of the options listed.

Reported-by: Yanliang Lei
Author: Bharath Rupireddy
Discussion: https://postgr.es/m/16972-42d4b0c15aa1d5f5@postgresql.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1599e7b375127cac81b539d2c69d3faf7598509b

Modified Files
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doc/src/sgml/config.sgml | 88 ++++++++++++++++++++++++------------------------
1 file changed, 44 insertions(+), 44 deletions(-)