External product links
You can now configure products to link to external URLs (separate applications, third-party documentation, or other external resources) instead of documentation within your site.
External products appear in the product switcher alongside internal products but navigate users to the specified URL when selected.  Unlike internal products, external products are defined directly in docs.yml using href—no standalone product .yml file is needed.
To define an external product, add an item to the products list in docs.yml with an href instead of a path:
docs.yml
Visit the product switching documentation to learn more.