doc: in contrib-spi, mention and link to the meaning of SPI

Bruce Momjian <bruce@momjian.us>

Commit: 19eb7f84e75f592c7a7134d2d02105a3d44ff7e7
Author: Bruce Momjian <bruce@momjian.us>
Date: 2018-01-31T21:54:33Z
Releases: 10.2
doc:  in contrib-spi, mention and link to the meaning of SPI

Also remove outdated comment about SPI subtransactions.

Reported-by: gregory@arenius.com

Discussion: https://postgr.es/m/151726276676.1240.10501743959198501067@wrigleys.postgresql.org

Backpatch-through: 9.3

Files

PathChange+/−
doc/src/sgml/contrib-spi.sgml modified +3 −1
doc/src/sgml/spi.sgml modified +1 −2

Documentation touched