[AUR-411] Adopt to Example2 project (#28)

Add the chatbot from Example2. Create the UI for chat.

knowledgehub/llms/__init__.py

@@ -0,0 +1,13 @@
+from langchain.schema.messages import AIMessage, SystemMessage
+
+from .chats import AzureChatOpenAI, ChatLLM
+from .chats.base import BaseMessage, HumanMessage
+
+__all__ = [
+    "ChatLLM",
+    "AzureChatOpenAI",
+    "BaseMessage",
+    "HumanMessage",
+    "AIMessage",
+    "SystemMessage",
+]