Point to diego-release/CONTRIBUTING.md for docs on how to SQL
Point to diego-release/CONTRIBUTING.md for docs on how to SQL

[#113854821]

Signed-off-by: Luan Santos <509a85c757dc22c0257f4655fb3fb682d42f965b@pivotal.io>

cloudfoundry-incubator/bbs,cloudfoundry-incubator/bbs