chore: use npm2yarn consistently

Author: nickserv

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

@@ -32,7 +32,7 @@ value is `7000`. You will see `...` in the console, when the DOM content is
 stripped off, because of the length you have set or due to default size limit.
 Here's how you might increase this limit when running tests:
 
-```
+```bash npm2yarn
 DEBUG_PRINT_LIMIT=10000 npm test
 ```
 
@@ -46,7 +46,7 @@ colors, such as in cases where the output is written to a log file for debugging
 purposes. You can use the environment variable `COLORS` to explicitly force the
 colorization off or on. For example:
 
-```
+```bash npm2yarn
 COLORS=false npm test
 ```
 

docs/ecosystem-user-event.mdx

@@ -3,9 +3,6 @@ id: ecosystem-user-event
 title: user-event v13
 ---
 
-import Tabs from '@theme/Tabs'
-import TabItem from '@theme/TabItem'
-
 [`user-event`][gh] is a companion library for Testing Library that provides more
 advanced simulation of browser interactions than the built-in
 [`fireEvent`](dom-testing-library/api-events.mdx#fireevent) method.
@@ -21,23 +18,10 @@ fixes and new features.
 
 ## Installation
 
-  <Tabs defaultValue="npm" values={[{ label: 'npm', value: 'npm' }, { label: 'Yarn', value: 'yarn' }]}>
-  <TabItem value="npm">
-
-```sh
+```bash npm2yarn
 npm install --save-dev @testing-library/user-event @testing-library/dom
 ```
 
-  </TabItem>
-  <TabItem value="yarn">
-
-```sh
-yarn add --dev @testing-library/user-event @testing-library/dom
-```
-
-  </TabItem>
-  </Tabs>
-
 Now simply import it in your tests:
 
 ```js

docs/user-event/install.mdx

@@ -3,29 +3,10 @@ id: install
 title: Installation
 ---
 
-import Tabs from '@theme/Tabs'
-import TabItem from '@theme/TabItem'
-
-<Tabs defaultValue="npm" values={[
-    { label: 'npm', value: 'npm' },
-    { label: 'Yarn', value: 'yarn' },
-]}>
-<TabItem value="npm">
-
-```sh
+```bash npm2yarn
 npm install --save-dev @testing-library/user-event
 ```
 
-</TabItem>
-<TabItem value="yarn">
-
-```sh
-yarn add --dev @testing-library/user-event
-```
-
-</TabItem>
-</Tabs>
-
 Note that `@testing-library/user-event` requires `@testing-library/dom`.
 
 If you use one of the