Matt's review (partial)

Co-authored-by: Matt <github@nospam.33m.co>

docs/src/pages/guides/testing/testing.md

@@ -4,14 +4,14 @@
 
 ## Userspace
 
-We recommend testing your application without tying the tests too close to Material-UI.
-This is how we test our components internally.
+It's generally recommended to test your application without tying the tests too closely to Material-UI.
+This is how Material-UI components are tested internally.
 A library that has a first-class API for this approach is [`@testing-library/react`](https://testing-library.com/docs/react-testing-library/intro).
 
-For example, when rendering a `TextField` your test should not need to query for the specific Material-UI instance of the `TextField` but rather for the `input`, or the `[role="textbox"]`.
+For example, when rendering a `TextField` your test should not need to query for the specific Material-UI instance of the `TextField` but rather for the `input`, or `[role="textbox"]`.
 
 By not relying on the React component tree you make your test more robust against internal changes in Material-UI or, if you need snapshot testing, adding additional wrapper components such as context providers.
-Though we don't recommend snapshot testing.
+We don't recommend snapshot testing though.
 ["Effective snapshot testing" by Kent C. Dodds](https://kentcdodds.com/blog/effective-snapshot-testing) goes into more details why snapshot testing might be misleading for React component tests.
 
 ## Internal