.Net: Add an example showing how to use the OpenAI response format pr…

…operty (#4678)

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dotnet/samples/KernelSyntaxExamples/Getting_Started/Step1_Create_Kernel.cs

@@ -47,6 +47,11 @@ public async Task RunAsync()
         // Example 4. Invoke the kernel with a templated prompt and execution settings
         arguments = new(new OpenAIPromptExecutionSettings { MaxTokens = 500, Temperature = 0.5 }) { { "topic", "dogs" } };
         WriteLine(await kernel.InvokePromptAsync("Tell me a story about {{$topic}}", arguments));
+
+        // Example 5. Invoke the kernel with a templated prompt and execution settings configured to return JSON
+#pragma warning disable SKEXP0013
+        arguments = new(new OpenAIPromptExecutionSettings { ResponseFormat = "json_object" }) { { "topic", "chocolate" } };
+        WriteLine(await kernel.InvokePromptAsync("Create a recipe for a {{$topic}} cake in JSON format", arguments));
     }
 
     public Step1_Create_Kernel(ITestOutputHelper output) : base(output)