message: docs: Clarify how panic mode works with priorities
diff: @@ -124,6 +124,12 @@ runtime as well as in the :ref:`cluster configuration
  is used to avoid a situation in which host failures cascade throughout the cluster as load
  increases.
  +Note that panic thresholds are *per-priority*. This means that if the percentage of healthy nodes
  +in a single priority goes below the threshold, that priority will enter panic mode. In general
  +it is discouraged to use panic thresholds in conjunction with priorities, as by the time enough
  +nodes are unhealthy to trigger the panic threshold most of the traffic should already have spilled
  +over to the next priority level.
  +
  .. _arch_overview_load_balancing_priority_levels:
  Priority levels
  