Feedback from Engineering and Community Relations about support code contributions

Follow-up to #3050 (closed) & support-training!586 (comment 495307338)

We might not want to funnel Support Engineers towards good for new contributors issues too much. @dplanella pointed out that we shouldn't "reduce the number of issues our wider community can get started with" too much. Possibly, we need a different label to track engineering issues that would make good examples in the code contributions module, if it becomes very popular.

Let's observe this for 3 months and discuss here. cc @cynthia & @splattael