Add an example of WITH (UPDATE RETURNING) INSERT to the INSERT ref page.
Add an example of WITH (UPDATE RETURNING) INSERT to the INSERT ref page.

Per a discussion with Gavin Flower.  This barely scratches the surface
of potential WITH (something RETURNING) use cases, of course, but it's
one of the simplest compelling examples I can think of.

pavanvd/postgres-xl,lisakowen/gpdb,adam8157/gpdb,50wu/gpdb,greenplum-db/gpdb,adam8157/gpdb,ashwinstar/gpdb,yazun/postgres-xl,lisakowen/gpdb,adam8157/gpdb,lisakowen/gpdb,Postgres-XL/Postgres-XL,jmcatamney/gpdb,ovr/postgres-xl,xinzweb/gpdb,kmjungersen/PostgresXL,Postgres-XL/Postgres-XL,arcivanov/postgres-xl,oberstet/postgres-xl,jmcatamney/gpdb,kmjungersen/PostgresXL,oberstet/postgres-xl,lisakowen/gpdb,lisakowen/gpdb,ashwinstar/gpdb,postmind-net/postgres-xl,snaga/postgres-xl,ovr/postgres-xl,50wu/gpdb,adam8157/gpdb,Postgres-XL/Postgres-XL,jmcatamney/gpdb,postmind-net/postgres-xl,techdragon/Postgres-XL,50wu/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,pavanvd/postgres-xl,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,tpostgres-projects/tPostgres,pavanvd/postgres-xl,greenplum-db/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,zeroae/postgres-xl,50wu/gpdb,techdragon/Postgres-XL,zeroae/postgres-xl,snaga/postgres-xl,oberstet/postgres-xl,adam8157/gpdb,xinzweb/gpdb,techdragon/Postgres-XL,xinzweb/gpdb,techdragon/Postgres-XL,tpostgres-projects/tPostgres,jmcatamney/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ovr/postgres-xl,jmcatamney/gpdb,50wu/gpdb,kmjungersen/PostgresXL,yazun/postgres-xl,xinzweb/gpdb,50wu/gpdb,arcivanov/postgres-xl,zeroae/postgres-xl,yazun/postgres-xl,oberstet/postgres-xl,greenplum-db/gpdb,yazun/postgres-xl,arcivanov/postgres-xl,ashwinstar/gpdb,tpostgres-projects/tPostgres,xinzweb/gpdb,jmcatamney/gpdb,lisakowen/gpdb,ovr/postgres-xl,snaga/postgres-xl,snaga/postgres-xl,greenplum-db/gpdb,postmind-net/postgres-xl,kmjungersen/PostgresXL,xinzweb/gpdb,50wu/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,Postgres-XL/Postgres-XL,ashwinstar/gpdb,arcivanov/postgres-xl,ovr/postgres-xl,pavanvd/postgres-xl,oberstet/postgres-xl,greenplum-db/gpdb,snaga/postgres-xl,postmind-net/postgres-xl,adam8157/gpdb,jmcatamney/gpdb,lisakowen/gpdb,arcivanov/postgres-xl,yazun/postgres-xl,kmjungersen/PostgresXL,arcivanov/postgres-xl,tpostgres-projects/tPostgres,tpostgres-projects/tPostgres,xinzweb/gpdb,adam8157/gpdb,zeroae/postgres-xl,postmind-net/postgres-xl,pavanvd/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,zeroae/postgres-xl,ashwinstar/gpdb