group commands and make features/options visible

cmd/restic/cmd_features.go

@@ -31,7 +31,7 @@ EXIT STATUS
 Exit status is 0 if the command was successful.
 Exit status is 1 if there was any error.
 `,
-	Hidden:            true,
+	GroupID:           cmdGroupAdvanced,
 	DisableAutoGenTag: true,
 	RunE: func(_ *cobra.Command, args []string) error {
 		if len(args) != 0 {