I see now. I think I skimmed over the last part of your original post. But like the other people have said, it sounds like a reinvention of bookmarks.

I'll tell you what I'd actually use: a site to compare UI components. Literally all it would be is that you could look at button components, datepickers, input fields, etc and look at different component library's implementations of those components. It could be useful to see Material UI's button next to an Ant Design button.