feat(esm): update package.json for esm

[AnotherBrynAlt]

Updates the package.json to be usable in Typescript ESM projects. This worked for me by changing downstream.

https://www.typescriptlang.org/docs/handbook/esm-node.html#packagejson-exports-imports-and-self-referencing

https://nodejs.org/api/packages.html#packages_exports