Streamlit fixed / sticky container

I realized that quite often I need a part of my app to be always visible for user. I created a simple wrapper for st.container that uses some CSS tricks. It supports both fixed and sticky options, custom margins and it switch its color when the user change the theme.

Iโ€™m leaving the link on Github Gists in case of future updates

Let me know if itโ€™s not acceptable and itโ€™s better to send the code right here :raised_hands:t3: