My only complaint with Leaflet is that they haven't done anything to support older versions. At an old workplace, we were stuck on an older version for a while due to incompatibilities, and having never used Leaflet before I needed to see how to use the specific version we were on.

I ended up having to clone the repo where the docs were, checkout the commit released for that version and build the docs myself. Maybe I'm spoiled by react-router's phenomenal handling of outdated docs, but it was a pretty terrible experience.