Обсуждение: pgsql: Rework SQL/JSON documentation

Rework SQL/JSON documentation

This makes the documentation conform more closely the style of other
function sections.

Includes suggestions from Erik Rijkers, Alvaro Herrera, and Justin
Pryzby.

Discussion: https://postgr.es/m/CAKFQuwaq5Ny6d3nWbJo=QO4RmhSk9JD8zrkURLR-wWmB2Pkz7Q@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/a1e7616d6e1e8056b6eae6d68be9e1e658afaf96

Modified Files
--------------
doc/src/sgml/func.sgml | 2642 +++++++++++-------------------------------------
1 file changed, 580 insertions(+), 2062 deletions(-)