update app add privacy disclaimer and duplication recommendation

app.py

@@ -13,6 +13,16 @@ semantic_model = SentenceTransformer('sentence-transformers/all-MiniLM-L6-v2')
 def main():
     st.title("PDF Topic Grouping App")
 
+    st.warning("""
+    **Warning**: Do not enter confidential data into this app when it is running in the cloud. 
+    Your information may not be secure.
+    """)
+
+    st.warning("""
+    **Important**: This Space is shared with other users, meaning others can view your results and data. 
+    Please duplicate this Space to your own Hugging Face account for privacy and security.
+    """)
+
     # Step 1: Upload PDFs
     uploaded_files = st.file_uploader("Upload PDFs", type="pdf", accept_multiple_files=True)