Add application file

app.py

@@ -1,4 +1,5 @@
 import streamlit as st
 
-x = st.slider('Select a value')
-st.write(x, 'squared is', x*x)
+st.title("Hello, Streamlit!")
+name = st.text_input("What's your name?")
+st.write(f"Hello, {name}!")