GitLab Pages offers us a great way of internal documentation-presentation (javadoc, jsdoc, etc.) and and acts as a static document repository for things like our checkstyle-configuration, which makes it a flexible and powerful part of the GitLab infrastructure.
While there are obviously other options like a normal directory on the servers or a fully-fledged website that uses the gitlab-api to display this data, we decided to use Gitlab Pages as we can deploy to the page as a part of our gitlab ci pipeline.