Update app.py

app.py

@@ -2,7 +2,7 @@ import streamlit as st
 import langcodes
 
 # https://huggingface.co/blog/streamlit-spaces
-langtext = st.text_input("language lookup using https://github.com/rspeer/langcodes", "en")
+langtext = st.text_input("language lookup using https://github.com/rspeer/langcodes, see also https://r12a.github.io/app-subtags/", "en")
 
 if langcodes.tag_is_valid(langtext):
   st.write(f"{langtext} is already a valid BCP-47 language tag")