Updating production config document with new gitlab railsSecret key

General MR

Summary

Updating production recommendation documentation to show use of available railsSecret key for Gitlab.

Follow on to MR !2689 (merged)

added statusdoing label

assigned to @ryan.j.garcia

added kinddocs label

changed the description

added statusreview label and removed statusdoing label

changed milestone to %2.1.0

requested review from @ryan.thompson.44, @echuang, @micah.nagel, @ronwebb, @rob.ferguson, and @LynnStill

approved this merge request

merged

mentioned in commit 60e7d08a