Clarify instructions for AWS reason

[kellyarwine]

For the Course maintenance swarm event, I attempted to take this course to replicate two issues that had been reported. While taking the course, I found the following issue:

• The instructions state to just type in a region but it is harder than that. You need to look up the region code on AWS for this to work. Also, it would be great if there were steps listed to help you troubleshoot when you add the "staging" label and you don't get the desired outcome. I got the region wrong. Tried to fix it, tried to re-run jobs...it was all still failing. I went and dug into the code and saw that the region change needed to be on main, so I tried to fix it there. Ended up confused and ran out of time so I wasn't able to complete the course.