Wait for a user's input before showing design patterns menu

* Adding ReadLine to allow user to read design pattern output

* suggested changes to add private method to notify user

* white space for readability

* Reorder methods

Co-authored-by: Nemanja Rogic <nemanjarogic@microsoft.com>

Author: kdk1116

src/DesignPatternsLibrary/Program.cs

@@ -19,6 +19,7 @@ private static void Main(string[] args)
             }
 
             Executors[choiceKey].Execute();
+            WaitForContinuationSignal();
         }
 
         Console.WriteLine("Thank you!");
@@ -69,4 +70,12 @@ private static bool IsChoiceUnsupported(string? choice, out int choiceKey)
         choiceKey = key;
         return false;
     }
+
+    private static void WaitForContinuationSignal()
+    {
+        Console.ForegroundColor = ConsoleColor.DarkGreen;
+        Console.WriteLine("\n\nExecution results can be found above. Press ENTER to continue.");
+        Console.ReadLine();
+        Console.ResetColor();
+    }
 }