add basic create and list reminder api

Budet-cho-bot/Models/CronRecord.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Budet_cho_bot.Models
+{
+    public class CronRecord
+    {
+        public DateTimeOffset LastRun { set; get; }
+        public TimeSpan Period { set; get; }
+        public bool IsOneShot { set; get; }
+    }
+}