Update utils/prompts.py

utils/prompts.py

@@ -10,7 +10,7 @@ def create_qa_prompt() -> PromptTemplate:
     Prompt for retrieval QA chain
     """
 
-    template = """\n\nHuman: Use the following pieces of context to answer the question at the end.
+    template = """\n\nHuman: Use the following pieces of context to answer the question at the end. If answer is not clear, say I DON"T KNOW
 
 {context}