added introductory prompt

backend.py

@@ -7,8 +7,6 @@ from llama_index.embeddings.instructor import InstructorEmbedding
 import gradio as gr
 from llama_index.core import Settings, VectorStoreIndex, SimpleDirectoryReader, PromptTemplate, load_index_from_storage, StorageContext
 from llama_index.core.node_parser import SentenceSplitter
-from huggingface_hub import hf_hub_download
-from llama_cpp import Llama
 import spaces
 from huggingface_hub import login
 from llama_index.core.memory import ChatMemoryBuffer
@@ -76,7 +74,7 @@ def build_index(path: str):
 
 
 
-@spaces.GPU(duration=90)
+@spaces.GPU(duration=20)
 def handle_query(query_str: str, 
                  chat_history: list[tuple[str, str]]) -> Iterator[str]:
     
@@ -90,7 +88,6 @@ def handle_query(query_str: str,
                     ]
                 )
     
-    
     if not session_state["index"]:
         matched_path = None
         words = query_str.lower()