Add new project starring topic to global navigation

What does this MR do and why?

For: technical-writing#1075, and as a companion to gitlab!168481 (merged), add now split of project starring API documentation to global navigation.

Screenshots, screen recordings, or links to review app

https://eread-add-new-project-starring-topic-to-global-nav.docs.gitlab-review.app/ee/api/project_starring.html

Merge request acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this merge request.