cli: add ls alias for the list subcommand

src/cli.rs

@@ -39,6 +39,7 @@ pub enum SubCommand {
     Edit(self::edit::Args),
     Remove(self::remove::Args),
     Priority(self::priority::Args),
+    #[clap(alias("ls"))]
     List,
     Start(self::start::Args),
     Pause,