accept notes via --play or -p

src/flags.rs

@@ -13,6 +13,9 @@ pub struct Flags {
 
     #[arg(long, default_value = "super_small_font.sf2")]
     pub sound_font: String,
+
+    #[arg(short, long, default_value = "c 2e+")]
+    pub play: Option<String>,
 }
 
 impl Flags {