docs: fix note not closed (#1395)

Author: MatanBobi

docs/react-testing-library/example-intro.mdx

@@ -66,10 +66,12 @@ test('loads and displays greeting', async () => {
 See the following sections for a detailed breakdown of the test
 
 :::note 
+
 We recommend using the
 [Mock Service Worker (MSW)](https://github.com/mswjs/msw) library to
 declaratively mock API communication in your tests instead of stubbing
 `window.fetch`, or relying on third-party adapters.
+
 :::
 
 ```jsx title="__tests__/fetch.test.jsx"