add help command

src/main.rs

@@ -101,7 +101,9 @@ enum LeetCommand {
     #[command(description = "get scores")]
     Scores,
     #[command(description = "get current time info")]
-    Time
+    Time,
+    #[command(description = "show help about leetbot")]
+    Help
 }
 
 #[derive(Error,Debug)]
@@ -195,6 +197,9 @@ leet is at: {}, in {} seconds",
 	    );
 
 	    bot.send_message(message.chat.id, msg).await?;
+	},
+        LeetCommand::Help => {
+	    bot.send_message(message.chat.id, LeetCommand::descriptions().to_string()).await?;
 	}
     }