Add demo example

examples/Console/Demo/ExceptionGenerator.cs

@@ -0,0 +1,31 @@
+using System;
+using Spectre.Console;
+
+namespace Demo
+{
+    public static class ExceptionGenerator
+    {
+        public static Exception GenerateException()
+        {
+            try
+            {
+                SomeOperation();
+                throw new InvalidOperationException();
+            }
+            catch (Exception ex)
+            {
+                return ex;
+            }
+        }
+
+        private static void SomeOperation()
+        {
+            SomeOperationGoingWrong();
+        }
+
+        private static void SomeOperationGoingWrong()
+        {
+            throw new InvalidOperationException("Something went very wrong!");
+        }
+    }
+}