message: Fix keyboard documentation
diff: //! match key {
  //! // Quit if Shift+Ctrl+Q is pressed.
  //! KeyCode::Q => {
  -//! if mods.contains(KeyMods::SHIFT & KeyMods::CTRL) {
  +//! if mods.contains(KeyMods::SHIFT) && mods.contains(KeyMods::CTRL) {
  //! println!("Terminating!");
  //! event::quit(ctx);
  //! } else if mods.contains(KeyMods::SHIFT) || mods.contains(KeyMods::CTRL) {
  