Clarify podTerminationGracePeriod docs (aws#351)

Fixes aws#348

config/helm/aws-node-termination-handler/README.md

@@ -55,8 +55,8 @@ The configuration in this table applies to both queue-processor mode and IMDS mo
 Parameter | Description | Default
 --- | --- | ---
 `deleteLocalData` | Tells kubectl to continue even if there are pods using emptyDir (local data that will be deleted when the node is drained). | `true`
-`gracePeriod` | (DEPRECATED: Renamed to podTerminationGracePeriod) The time in seconds given to each pod to terminate gracefully. If negative, the default value specified in the pod will be used. | `30`
-`podTerminationGracePeriod` | The time in seconds given to each pod to terminate gracefully. If negative, the default value specified in the pod will be used. | `30`
+`gracePeriod` | (DEPRECATED: Renamed to podTerminationGracePeriod) The time in seconds given to each pod to terminate gracefully. If negative, the default value specified in the pod will be used, which defaults to 30 seconds if not specified. | `-1`
+`podTerminationGracePeriod` | The time in seconds given to each pod to terminate gracefully. If negative, the default value specified in the pod will be used, which defaults to 30 seconds if not specified. | `-1`
 `nodeTerminationGracePeriod` | Period of time in seconds given to each NODE to terminate gracefully. Node draining will be scheduled based on this value to optimize the amount of compute time, but still safely drain the node before an event. | `120`
 `ignoreDaemonSets` | Causes kubectl to skip daemon set managed pods | `true`
 `instanceMetadataURL` | The URL of EC2 instance metadata. This shouldn't need to be changed unless you are testing. | `http://169.254.169.254:80`