Update rag.py

app/rag.py

@@ -19,8 +19,9 @@ class ChatPDF:
         self.text_splitter = RecursiveCharacterTextSplitter(chunk_size=2048, chunk_overlap=128)
         self.prompt = PromptTemplate.from_template(
             """
-            You are an assistant for question-answering tasks. Use the following pieces of context 
-            to answer the question. If you don't know the answer, just say that you don't know. 
+            You are an assistant for question-answering tasks. Use the following pieces of retrieved context to 
+            answer the question. If you don't know the answer, just say that you don't know. Use three sentences
+             maximum and keep the answer concise. 
             Question: {question} 
             Context: {context} 
             Answer: