Added more details about managing chat history

Author: kevinguo-ed

aspnetcore/tutorials/ai-powered-group-chat/ai-powered-group-chat.md

@@ -55,9 +55,24 @@ await foreach (var completion in chatClient.CompleteChatStreamingAsync(messagesI
 }
 ```
 
-The chat history is managed by `GroupHistoryStore`, which stores messages for context. It includes both user and assistant messages to maintain conversation continuity.
+### Maintaining context with history
+
+Every request to [Open AI's Chat Completions API](https://platform.openai.com/docs/guides/chat-completions) is stateless - Open AI doesn't store past interactions. In a chat application, what a user or an assistant has said is important for generating a response that's contextually relevant. We can achieve this by including chat history in every request to the Completions API. 
+
+The `GroupHistoryStore` class manages chat history for each group. It stores messages posted by both the users and AI assistants, ensuring that the conversation context is preserved across interactions. This context is crucial for generating coherent AI responses.
+
+```csharp
+// Store message generated by AI-assistant in memory
+public void UpdateGroupHistoryForAssistant(string groupName, string message)
+{
+    var chatMessages = _store.GetOrAdd(groupName, _ => InitiateChatMessages());
+    chatMessages.Add(new AssistantChatMessage(message));
+}
+```
+
 ```csharp
-public void UpdateGroupHistoryForAssistant(string groupName, string message) { ... }
+// Store message generated by users in memory
+_history.GetOrAddGroupHistory(groupName, userName, message);
 ```
 
 ### Streaming AI responses
@@ -74,17 +89,6 @@ if (totalCompletion.Length - lastSentTokenLength > 20)
 }
 ``` 
 
-### Maintaining context with history
-
-The `GroupHistoryStore` class manages the chat history for each group. It stores both user and AI messages, ensuring that the conversation context is preserved across interactions. This context is crucial for generating coherent AI responses.
-```csharp
-public void UpdateGroupHistoryForAssistant(string groupName, string message)
-{
-    var chatMessages = _store.GetOrAdd(groupName, _ => InitiateChatMessages());
-    chatMessages.Add(new AssistantChatMessage(message));
-}
-```
-
 ## Explore further
 
 This project opens up exciting possibilities for further enhancement: