fantasyland/fantasy-land ? reverse-engineered prompt

Build me a clean documentation site and package for the Fantasy Land JavaScript spec.

I want it to clearly explain the common algebraic structures used in functional JavaScript, like Functor, Monad, Semigroup, Monoid, Foldable, Traversable, and the rest of the related types. The page should show the relationships between them, list the required methods, and explain the laws in simple language with examples people can actually follow.

Please make it feel polished and easy to browse, with a main README style page, a visible spec index, and the ability to jump between sections. Include the type definitions or exports needed for consumers, and make sure the project has tests that verify the documentation and names stay consistent.

If you need to check current best practices for docs or TypeScript support, look up the latest info online first.