rofl: Add topup alias for top-up

Author: matevz

cmd/rofl/machine/mgmt.go

@@ -188,6 +188,7 @@ var (
 	topUpCmd = &cobra.Command{
 		Use:   "top-up [<machine-name> | <provider-address>:<machine-id>]",
 		Short: "Top-up payment for a machine",
+		Aliases: []string{"topup"},
 		Args:  cobra.MaximumNArgs(1),
 		Run: func(_ *cobra.Command, args []string) {
 			txCfg := common.GetTransactionConfig()