Added retriever too

app.py

@@ -43,9 +43,19 @@ if html_file is not None:
     index = VectorStoreIndex.from_documents(
         documents, show_progress=True, metadata={"source": "HTML"}, service_context=service_context)
 
+    retriever = index.as_retriever()
+
+    ranked_nodes = retriever.retrieve(
+        "Get me all the information about the product")
+
+    with st.expander("Ranked Nodes"):
+        for node in ranked_nodes:
+            st.write(node.node.get_content(), "-> Score:", node.score)
+
     query_engine = index.as_query_engine(
         filters=filters, service_context=service_context)
 
-    response = query_engine.query("Get me all the information about the product")
+    response = query_engine.query(
+        "Get me all the information about the product")
 
     st.write(response)