fix: importing missing ReactElement type (#851)

Author: marceloadsj

docs/react-testing-library/setup.mdx

@@ -78,7 +78,7 @@ export { customRender as render }
 ```
 
 ```tsx title="test-utils.tsx"
-import React, { FC } from 'react'
+import React, { FC, ReactElement } from 'react'
 import { render, RenderOptions } from '@testing-library/react'
 import { ThemeProvider } from 'my-ui-lib'
 import { TranslationProvider } from 'my-i18n-lib'