docs: short aliases [ci skip]

cli/app/volume.go

@@ -63,7 +63,7 @@ var appVolumeListCommand = &cli.Command{
 var appVolumeRemoveCommand = &cli.Command{
 	Name:    "remove",
 	Usage:   "remove volume(s) associated with an app",
-	Aliases: []string{"rm", "delete"},
+	Aliases: []string{"rm"},
 	Flags: []cli.Flag{
 		internal.ForceFlag,
 	},
@@ -105,7 +105,8 @@ var appVolumeRemoveCommand = &cli.Command{
 
 var appVolumeCommand = &cli.Command{
 	Name:      "volume",
-	Usage:     "List or remove volumes associated with app",
+	Aliases:   []string{"v"},
+	Usage:     "Manage app volumes",
 	ArgsUsage: "<command>",
 	Subcommands: []*cli.Command{
 		appVolumeListCommand,