Update help

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

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

@@ -1,15 +1,21 @@
 package chmod
 
-import "github.com/spf13/cobra"
+import (
+	"github.com/spf13/cobra"
+)
 
 var (
 	baseCmd = &cobra.Command{
-		Use:   "chmod [flags] (overlay kind) (overlay name) (path) (mode)",
-		Short: "Change file permissions within an overlay",
-		Long: "This command will allow you to change the permissions of a file within an\n" +
-			"overlay.",
-		RunE: CobraRunE,
-		Args: cobra.ExactArgs(4),
+		DisableFlagsInUseLine: true,
+		Use:                   "chmod [OPTIONS] {runtime|system} OVERLAY_NAME FILENAME MODE",
+		Short:                 "Change file permissions in an overlay",
+		Long: `Changes the permissions of a single FILENAME within an overlay specified by
+overlay type (system or runtime) and its OVERLAY_NAME.
+
+You can use any MODE format supported by the chmod command.`,
+		Example: "wwctl overlay chmod system default /etc/hostname.ww 0660",
+		RunE:    CobraRunE,
+		Args:    cobra.ExactArgs(4),
 	}
 )