Add project files

ConsoleApp1/ISystem.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace ConsoleApp1
+{
+    internal interface ISystem
+    {
+        bool Start();
+        void Restart();
+        void Quit();
+    }
+}