Fractional-indexing

🎁 Features

- None

🐛 Fixes

- Fix issue with case where the alphabet did not start with `'0'` 15

🎁 Features

- Allow `undefined` to be used alongside `null` for arguments 13

🐛 Fixes

None

This is now a [Pure ESM Package](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c).

If you need CommonJS you can still use the 2.x releases.

- Adds generateNKeysBetween