2019Q3 Revisit UX Scorecard for identify and troubleshoot performance issues

Follow up from: https://gitlab.com/gitlab-org/gitlab-ee/issues/11713

Create an issue to revisit the same JTBD the following quarter to see if we have made improvements. We will use the grades to monitor progress toward improving the overall quality of our user experience

Overall updated grade: Negative, C+

New video outlining the experience of setting up the metrics dashboard.