Docs: Nav bar issue with internal links

It is unclear whether this behavior is intentional or a bug. When navigating the documentation, selecting an internal hyperlink that points to a page in a different directory does not update the navbar to reflect the new location.

This behavior appears inconsistent. In my testing, navigation works correctly for pages under the Prometheus Server and Alertmanager sections, but not for other directories. There may be additional cases where this occurs.

##Steps to reproduce

1. Open the FAQ page: https://prometheus.io/docs/introduction/faq/
2. Select the service discovery link.
3. Observe that the navbar does not update to reflect the new page location.

Note: Several other examples do exist,

##Expected behavior

The navbar should update to show the current page’s location within the documentation hierarchy after navigating through an internal link.

##Actual behavior

The content changes, but the navbar continues to display the previous section.

##Additional notes

The observation regarding the Prometheus Server and Alertmanager directories is based on limited testing and may require further verification.

Start with the FAQ page and follow its service discovery internal link, then inspect how the documentation navbar determines the current page location. Compare this behavior with links under the Prometheus Server and Alertmanager sections. Done means the navbar reflects the destination page after internal navigation across documentation directories.