add missing Fl_MenuButtonType to cfl_enums
# Changelog
-## [1.0.22] - Unreleased
+## [1.0.22] - 2021-07-05
- Add `fn WidgetExt::is_same<W: WidgetExt>(&self, other: &W)`.
- Add WidgetExt::active and active_r.
- Add app::ready, check, release, reload_scheme, menu_line_spacing and set_menu_line_spacing.
