cleaned up .env to move Azure config to separate azure.yaml file

updated README.md to explain new config
added Azure yaml loader to config class
centralized model retrieval into config class
this commit effectively combines and replaces #700 and #580

scripts/llm_utils.py

@@ -9,7 +9,7 @@ def create_chat_completion(messages, model=None, temperature=None, max_tokens=No
     """Create a chat completion using the OpenAI API"""
     if cfg.use_azure:
         response = openai.ChatCompletion.create(
-            deployment_id=cfg.openai_deployment_id,
+            deployment_id=cfg.get_azure_deployment_id_for_model(model),
             model=model,
             messages=messages,
             temperature=temperature,