PreemptionToleration: 'to outside of the pod' -> 'externally'

kep/205-preemption-toleration/README.md

@@ -42,7 +42,7 @@ This plugin provides more flexible preemption behavior configuration by adding t
 
 ### Lower priority value but not-being-preempted priority
 
-Generally speaking, making a job be resumable after preemption, the job would need to preserve its state to outside of the pod, e.g. persistent volume, object storage, etc., at preemption and restore it at next restart (a.k.a check-pointing). However, when a job uses some proprietary tools that are not modifiable or do not support suspend/resume feature,  users would like to avoid being preempted. 
+Generally speaking, making a job be resumable after preemption, the job would need to preserve its state externally, e.g. persistent volume, object storage, etc., at preemption and restore it at next restart (a.k.a check-pointing). However, when a job uses some proprietary tools that are not modifiable or do not support suspend/resume feature,  users would like to avoid being preempted. 
 
 To achieve this, `PriorityClass` with a high priority value would be enough. But just giving high priority value causes preemption on any pods with lower priority values.  Sometimes, users don't want to do it.  In such a case, the job's priority is essentially low (i.e. the job is expected to run only when the cluster has a vacancy).  However, once scheduled, users don't want the pod to be preempted because the pod is difficult to export/import its state.