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/args.rs

@@ -8,6 +8,7 @@ use std::time::Duration;
 use crate::common::{Content, Style};
 
 #[derive(Parser)]
+#[command(version)]
 pub struct Args {
     #[arg(long, short, value_parser = parse_duration,
         help = "Countdown time to start from. Formats: 'ss', 'mm:ss', or 'hh:mm:ss'"
@@ -33,6 +34,9 @@ pub struct Args {
     #[arg(long, short = 's', value_enum, help = "Style to display time with.")]
     pub style: Option<Style>,
 
+    #[arg(long, value_enum, help = "Whether to open the menu or not.")]
+    pub menu: bool,
+
     #[arg(long, short = 'r', help = "Reset stored values to default.")]
     pub reset: bool,
 }