minor fix

app.py

@@ -73,7 +73,7 @@ async def init():
     
     
     # set up cached embeddings store
-    store = LocalFileStore("./cache/")
+    store = LocalFileStore("./.cache/")
     core_embeddings_model = OpenAIEmbeddings()
     embedder = CacheBackedEmbeddings.from_bytes_store(core_embeddings_model, 
                                                       store,