Lots of changes including: wwctl overlay list and framework for other commands

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

@@ -6,7 +6,7 @@ import (
 )
 
 var (
-	showCmd = &cobra.Command{
+	baseCmd = &cobra.Command{
 		Use:                "show",
 		Short:              "Show Warewulf Overlay objects",
 		Long:               "Warewulf show overlay objects",
@@ -21,12 +21,11 @@ func init() {
 
 // GetRootCommand returns the root cobra.Command for the application.
 func GetCommand() *cobra.Command {
-	return showCmd
+	return baseCmd
 }
 
 
 func CobraRunE(cmd *cobra.Command, args []string) error {
-
 	fmt.Printf("Show: Hello World\n")
 	return nil
 }