chore: document how to turn off dry-run mode in flags

main.go

@@ -77,7 +77,7 @@ func init() {
 	kingpin.Flag("master", "The address of the Kubernetes cluster to target").StringVar(&master)
 	kingpin.Flag("kubeconfig", "Path to a kubeconfig file").StringVar(&kubeconfig)
 	kingpin.Flag("interval", "Interval between Pod terminations").Default("10m").DurationVar(&interval)
-	kingpin.Flag("dry-run", "If true, don't actually do anything.").Default("true").BoolVar(&dryRun)
+	kingpin.Flag("dry-run", "Don't actually kill any pod. Turned on by default. Turn off with `--no-dry-run`.").Default("true").BoolVar(&dryRun)
 	kingpin.Flag("debug", "Enable debug logging.").BoolVar(&debug)
 	kingpin.Flag("metrics-address", "Listening address for metrics handler").Default(":8080").StringVar(&metricsAddress)
 	kingpin.Flag("grace-period", "Grace period to terminate Pods. Negative values will use the Pod's grace period.").Default("-1s").DurationVar(&gracePeriod)