Add in response as chat assistant message

[codemillmatt]

ai-samples/src/getting-started/01-HikerAI/Program.cs

Line 74 in 72529fd

Console.WriteLine($"\n\nAssistant >>> {assistantResponse.Content}");

Should we add the model's response in as a ChatRequestAssistantMessage? This way we can show it creating the chatbot-like experience?

[codemillmatt]

@FBoucher for visibility

[FBoucher]

fixed with #12