It's just my humble opinion, but some example apps will definitely help making a UI framework "ready for web" - a fully compatible TodoMVC app,
Realworld.io app, a Tailwind example with working build process, an app with some complex JS components (for table, select, richtext etc.), an animations example (CSS or JS based). Maybe it's just me, but I always check the examples first, if they are available for a library or framework.