Update app.py

app.py

@@ -1,6 +1,6 @@
 import streamlit as st
 import PyPDF2
-from extractive_model import summarize_with_textrank
+from extractive_summarization import summarize_with_textrank, summarize_with_lsa
 from abstractive_model import summarize_with_bart
 from keyword_extraction import extract_keywords
 from keyphrase_extraction import extract_sentences_with_obligations