add 'ilm show -t' to show a better visualization of a ilm policy (#57)

cmd/ilm.go

@@ -103,6 +103,15 @@ func IlmShow(conf *cfg.Config) *cli.Command {
 		Usage:     "show details about an index lifecycle policy",
 		UsageText: "show <policy>",
 
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:        "tree",
+				Usage:       "display policy as a tree",
+				Destination: &conf.Ilm.Tree,
+				Aliases:     []string{"t"},
+			},
+		},
+
 		Action: func(ctx context.Context, cmd *cli.Command) error {
 			policy := cmd.Args().Get(0)
 			if policy == "" {