Add example for tabs-placement: header with updated layout settings (#396)

Co-authored-by: Devin Logan <[email protected]>

Author: BipinRimal314

fern/products/docs/pages/navigation/images/tabs-sidebar.png

@@ -237,10 +237,18 @@ tabs:
 Here's an example of what the Tabs implementation looks like:
 
 <Frame>
-  ![Screenshot showing two vertically stacked tabs labeled API Reference and Help
-  Center](https://fern-image-hosting.s3.amazonaws.com/fern/tabs.png)
+  <img src="./images/tabs-sidebar.png" alt="Tabs displayed in the sidebar (default)" />
 </Frame>
 
+Tabs display in the left sidebar by default. To display them horizontally, set `tabs-placement` to `header` in your [layout configuration](/docs/customization/what-is-docs-yml#layout-configuration).
+
+<CodeBlock title="docs.yml">
+```yaml
+layout:
+  tabs-placement: header
+```
+</CodeBlock>
+
 ## Versions
 
 If you have multiple versions of your documentation, you can introduce a dropdown version selector by specifying the `versions`. For more information, check out our [documentation on versioning](/learn/docs/building-your-docs/versioning).