Add Scope line to burnup charts

Please add a Total Scope line to the burnup chart in the Chart Board. This would show the total number of story points (or points of business value) that WERE included in the selected version on each chart date.

The line would often be flat - i.e. a horizontal line at 20 if there are 20 story points (of all statuses) in the sprint. But the line would go up for days on which scope was added to the sprint.

To me this is the whole point of a burnup chart - if you have increasing scope you can see that you're still making progress but toward a moving target. A burndown chart shows this as a lack of progress.

The historical scope info required would also be very helpful in calculating velocity and planning new sprints.