this will be required starting January anyhow, see
https://www.rainviewer.com/api/transition-faq.html
already removed the rain layer in a past commit because it wasn't
working anymore
seems the radar layer with maxZoom 7 should stay working but i guess
i'll have to check for alternatives if it does not
the rate limit starting january should work ok with maxZoom 7 unless you
zoom into a lot of regions