Salmanap/fix config generator (#124)

* fixed environment variables issue with build. Now llm provider access keys are being written correctly

* fixed and verified that keys are being properly set when archgw is booted up

* removing leaf reference to a staged config file. not needed anymore

* minor fixes to get the build in more stable state

* minor fixes based on feedback

---------

Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-261.local>

demos/function_calling/arch_config.yaml

@@ -17,14 +17,14 @@ overrides:
 
 llm_providers:
   - name: open-ai-gpt-4
-    access_key: $OPENAI_API_KEY
+    access_key: OPENAI_API_KEY
     provider: openai
     model: gpt-4
     default: true
   - name: mistral-large-latest
-    access_key: $MISTRAL_API_KEY
+    access_key: MISTRAL_API_KEY
     provider: mistral
-    model: large-latest
+    model: mistral-large-latest
 
 system_prompt: |
   You are a helpful assistant.