Should we drop codrops from the list 🤔 

It’s not clear if this is still maintained:
https://tympanus.net/codrops/css_reference/

I’m missing a few thinks over there. For example the `:has()` pseudo-class.

I opened an issue for that: codrops/css-reference-issues#97

Let’s see if this is still alive.

cc// @uschmidt 