Multiwindow burn-rate alert

Also written: burn-rate alert, fast burn, slow burn

An alert on how fast an error budget is being spent that checks a long window (proving the problem is big) and a short one (proving it is still happening). For example, page at burn rate 14.4 over 1 hour and 5 minutes, and open a ticket at 6 over 6 hours and 30 minutes.