change naming of GUI class, fixate Form border, add published executable

Program.cs

@@ -17,7 +17,7 @@ namespace it_projekt
             Application.SetHighDpiMode(HighDpiMode.SystemAware);
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
-            Application.Run(new Form1());
+            Application.Run(new GUI());
         }
     }
 }