Updating dev dependencies to remove audit warnings, updating README & LICENSE copyright year, updating eslint rules, version bump to release new ESM support

Defaulting `options.cwd` to `process.cwd()`, passing `options.cwd` to `worker.js`, fixing `worker.js` by setting `global.__dirname` to `obj.cwd` on init, really fixes #10

Adding `require` to the inline script context for convenience, fixing API mistake by removing `close()` from the instance & updating README