This comment is not meant to be the main judgment on what is otherwise an interesting update, but:

> To focus on your content

shows a screenshot with extremely long text lines that are far harder to read than than when the sidebar thing helps keep the lines to a still-too-long-but-not-as-bad length. How does nobody at GitLab realize that you need some max-width or a container or something to keep text line length comfortably readable‽

(the same can be said for Hacker News, but everyone seems to know that it's ugly already)