Update streamlit.json (#790)

* Update streamlit.json

* Update widget.button.py

Author: sfc-gh-dmatthews

python/api-examples-source/widget.button.py

@@ -1,6 +1,7 @@
 import streamlit as st
 
-if st.button("Say hello"):
-    st.write("Why hello there")
+st.button('Reset', type='primary')
+if st.button('Say hello'):
+    st.write('Why hello there')
 else:
-    st.write("Goodbye")
+    st.write('Goodbye')