Add note about global DOM requirement for screen (testing-library#723)

Author: mathiassoeholm

docs/dom-testing-library/api-queries.mdx

@@ -26,7 +26,8 @@ an error if no elements match.
 
 `queryBy*` queries return the first matching node for a query, and return `null`
 if no elements match. This is useful for asserting an element that is not
-present. This throws an error if more than one match is found (use `queryAllBy` instead).
+present. This throws an error if more than one match is found (use `queryAllBy`
+instead).
 
 ### queryAllBy
 
@@ -86,6 +87,17 @@ document.body.innerHTML = exampleHTML
 const exampleInput = screen.getByLabelText(/example/i)
 ```
 
+> **Note**
+>
+> You need a global DOM environment to use `screen`. If you're using jest, with
+> the
+> [testEnvironment](https://jestjs.io/docs/en/configuration#testenvironment-string)
+> set to `jsdom`, a global DOM environment will be available for you.
+>
+> If you're loading your test with a `script` tag, make sure it comes after the
+> `body`. An example can be seen
+> [here](https://github.com/testing-library/dom-testing-library/issues/700#issuecomment-692218886).
+
 ### `screen.debug`
 
 For convenience screen also exposes a `debug` method in addition to the queries.

docs/react-testing-library/migrate-from-enzyme.mdx

@@ -13,9 +13,9 @@ with React Testing Library.
 
 React Testing Library is part of an open-source project named
 [Testing Library](https://github.com/testing-library). There are several other
-helpful tools and libraries in the Testing Library project which you can use
-to write more useful tests. Besides React Testing Library, here are some
-other Testing Library's libraries that can help you along the way:
+helpful tools and libraries in the Testing Library project which you can use to
+write more useful tests. Besides React Testing Library, here are some other
+Testing Library's libraries that can help you along the way:
 
 - **[@testing-library/jest-dom](https://github.com/testing-library/jest-dom)**:
   jest-dom provides a set of custom jest matchers that you can use to extend
@@ -49,9 +49,9 @@ development speed and productivity, since every small change requires rewriting
 some part of your tests, even if the change you made does not affect the
 component's output.
 
-Re-writing your tests in React Testing library is worthwhile, because you're trading
-tests that slow you down for tests that give you more confidence and increase
-your productivity in the long run.
+Re-writing your tests in React Testing library is worthwhile, because you're
+trading tests that slow you down for tests that give you more confidence and
+increase your productivity in the long run.
 
 ## How to migrate from Enzyme to React Testing Library?
 

docs/vue-testing-library/api.mdx

@@ -223,7 +223,8 @@ See a working example of `update` in the
 
 ## `cleanup`
 
-Unmounts Vue trees that were mounted with [render](#rendercomponent-options-callback).
+Unmounts Vue trees that were mounted with
+[render](#rendercomponent-options-callback).
 
 > If you are using an environment that supports `afterEach` hook (as in Jest),
 > there's no need to call `cleanup` manually. Vue Testing Library handles it for