fix(16916): adds React fragment support for Switcher's direct child

packages/react/docs/UsingFragmentsWithSwitcher.md

@@ -0,0 +1,43 @@
+The `Switcher` component is designed to have `SwitcherItem` components as its
+  direct children. However, there may be cases where you want to use React
+  Fragments or other nested structures within the `Switcher`. To accommodate we
+  recommend using the [`react-keyed-flatten-children`]
+  (https://www.npmjs.com/package/react-keyed-flatten-children#react-keyed-flatten-children)
+  package.
+
+### Using react-keyed-flatten-children
+
+The `react-keyed-flatten-children` package allows you to flatten arrays and
+React Fragments into a regular, one-dimensional array while preserving element
+and fragment keys. 
+
+1. Install the package:
+
+   ```
+   npm install react-keyed-flatten-children
+   ```
+
+2. Import and use in your component:
+
+   ```jsx
+   import flattenChildren from 'react-keyed-flatten-children';
+
+   const YourComponent = () => (
+     <Switcher>
+       {flattenChildren(
+         <>
+           <SwitcherItem>Item 1</SwitcherItem>
+           <SwitcherItem>Item 2</SwitcherItem>
+           <>
+             <SwitcherItem>Item 3</SwitcherItem>
+             <SwitcherItem>Item 4</SwitcherItem>
+           </>
+         </>
+       )}
+     </Switcher>
+   );
+   ```
+
+This approach allows you to use Fragments and nested structures with components
+like `<Switcher>` without modifying their source code. It preserves keys and
+props, ensuring stable rendering across updates.