Update app.py

app.py

@@ -34,7 +34,7 @@ def retriever_from_chroma(docs, search_type, k):
         os.makedirs(vectorstore_path)
     vectorstore = Chroma.from_documents(
         documents=docs, embedding=embeddings, persist_directory="docs/chroma/")
-    retriever = vectordb.as_retriever(search_type=search_type, search_kwargs={"k": k})
+    retriever = vectorstore.as_retriever(search_type=search_type, search_kwargs={"k": k})
     return retriever