doc: Documents new --metrics-host flag (#69)

kubereboot/kured#811

Signed-off-by: Nathan Kinkade <[email protected]>

content/en/docs/configuration.md

@@ -31,6 +31,7 @@ Flags:
       --message-template-drain string       message template used to notify about a node being drained (default "Draining node %s")
       --message-template-reboot string      message template used to notify about a node being rebooted (default "Rebooting node %s")
       --message-template-uncordon string    message template used to notify about a node being successfully uncordoned (default "Node %s rebooted & uncordoned successfully!")
+      --metrics-host string                 host where metrics will listen (default "")
       --metrics-port int                    port number where metrics will listen (default 8080)
       --node-id string                      node name kured runs on, should be passed down from spec.nodeName via KURED_NODE_ID environment variable
       --notify-url string                   notify URL for reboot notifications (cannot use with --slack-hook-url flags)
@@ -175,7 +176,10 @@ indicates the presence of the sentinel file:
 kured_reboot_required{node="ip-xxx-xxx-xxx-xxx.ec2.internal"} 0
 ```
 
-Note: Use `--metrics-port` to set a different post where metrics should listen.
+Note: Use `--metrics-host` and/or `--metrics-port` to set a different address
+where metrics should listen. The values of these flags will be put together
+like "<host>:<port>" to define a complete listen address for the metrics
+server.
 
 The purpose of this metric is to power an alert which will summon an
 operator if the cluster cannot reboot itself automatically for a