Doc: fix missing mention of procedure OUT parameters.
Small oversight in commit 2453ea142.
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/3ebc6d295705fec37dc8f57a4ece54b370f55f72
Modified Files
--------------
doc/src/sgml/plpgsql.sgml | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)