Update help

Signed-off-by: jcsiadal <jeremy.c.siadal@intel.com>

internal/app/wwctl/overlay/mkdir/root.go

@@ -6,9 +6,10 @@ import (
 
 var (
 	baseCmd = &cobra.Command{
-		Use:   "mkdir [flags] (overlay kind) (overlay name) (directory path)",
+		DisableFlagsInUseLine: true,
+		Use:   "mkdir [OPTIONS] {system|runtime} OVERLAY_NAME DIRECTORY",
 		Short: "Create a new directory within an Overlay",
-		Long:  "This command will allow you to create a new file within a given Warewulf overlay.",
+		Long:  "This command creates a new directory within the Warewulf OVERLAY_NAME.",
 		RunE:  CobraRunE,
 		Args:  cobra.MinimumNArgs(3),
 	}