feat(cli): arg --menu (#37)

- Add `--menu` to args
- Add `--version` to args
- Change default behavior: At a first run of the app, the menu will be shown by default (similar to what @tschinz suggested in #33). However, if an user hides the menu later and closes the app, the menu will be hidden again with a next start. Just because the app restores the last app state.

src/storage.rs

@@ -36,7 +36,7 @@ impl Default for AppStorage {
         const DEFAULT_COUNTDOWN: Duration = Duration::from_secs(60 * 10); /* 10min */
         AppStorage {
             content: Content::default(),
-            show_menu: false,
+            show_menu: true,
             style: Style::default(),
             with_decis: false,
             pomodoro_mode: PomodoroMode::Work,