jest.init.js does not load before test runs by default

[sethPoulin]

In the chapter mocking-global-objects.md, it's suggested to add the mock for the i18n library to the jest.init.js file, since this file "is loaded before the tests are run automatically." But this needs to be expressly configured by adding the following to the jest.config.js file:

export default {
    setupFiles: ["<rootDir>/jest.init.js"]
}

I'd suggest you add this to the documentation or suggest that users of the testing guide copy the jest.config.js file from the repo.

Thanks for putting this guide together!

[lmiller1990]

Good idea, I'd like to add this. Thanks for pointing this out! Would you like to make a PR?

[sethPoulin]

Sure, I'd be happy to.