Update app.py

app.py

@@ -11,6 +11,7 @@ from langchain.text_splitter import RecursiveCharacterTextSplitter
 from langchain.callbacks.streaming_stdout import StreamingStdOutCallbackHandler
 from langchain.vectorstores import Chroma
 from chromadb.utils import embedding_functions
+from langchain.embeddings import SentenceTransformerEmbeddings
 from langchain.embeddings import HuggingFaceBgeEmbeddings
 from langchain.document_loaders import (
     CSVLoader,