Careful identification of "dashboards"

@mhoeber , this came out of the issue that Alison Kuryla's course team had finding "dashboard" in the docs. The JIRA item in the name is for any changes for course re-run to the "My Courses" dashboard, and pointed at 2. There aren't any visible changes, so I spent a half hour going through and identifying the various dashboards in text for Alison instead. And found a couple missed "New Beta Instructor Dashboard" references too -- yuck!