title: How to add '@testing-library/jest-dom' globally?
body: <p>I saw in a project using <code>create-react-app</code> a file named <code>setupTest.js</code> which just imports <code>@testing-library/jest-dom</code> and the tests seems to use the extented <code>expect</code> version, like <code>.toBeInTheDocument</code>.</p>
  <p>I added the same file (<code>setupTest.js</code>) to my project but seems to be no effect.</p>
  <p>In other words, how can I import <code>@testing-library/jest-dom</code> globally instead of doing in every <code>.spec.ts</code> file?</p>