Add testing pipeline to database review process

We currently only trigger the testing pipeline manually, so one has to know about it and also use it. We can increase awareness and adoption by adding information about the testing pipeline to the database review documentation. MR authors should trigger the pipeline when they are ready for a review. They should look for any warnings and make adjustments as necessary.

We can also use the monitoring dashboard produced by #14 (closed) to see what the impact of our effort is.