Npm readme different to github

hi,

Please publish a new version with correct readme.

Npm readme says to use setupFiles which doesn't work.

Also if you could update the readme to be this:

globalSetup.js

```
const setTZ = require('set-tz');

module.exports = async () => {
  setTZ('UTC');
};
```

```
globalSetup: './globalSetup.js',
```