Provide structured data for breadcrumbs

Problem statement

GitLab provides breadcrumbs in its user interface that allows a user to understand the position of the page in the overall content hierarchy. The breadcrumbs, however, are not marked up in a manner that makes it easy for search engines to identify and use the data for enhanced search result rendering.

Job to be done

Implement JSON-LD format structured data for breadcrumbs as per guideline: https://developers.google.com/search/docs/data-types/breadcrumb