Redesign page settings page
### Problem to solve As part of the [Experience Baselines and Recommendations](https://about.gitlab.com/handbook/engineering/ux/experience-baseline-recommendations/) initiative, it was demonstrated the pages settings layout could use some improvement. Problems to solve: * Reduce the visual impact of remove pages section * Better connection between `New domain` and the domain list * Reduce confusion of the `Save` button * Provide an area for in UI documentation ### Intended users Users with projects that use any static website generator or plain HTML that wish to leverage GitLab pages. ### Proposal New page layout to address the above issues. ### Links / references [Experience Baselines and Recommendations](https://about.gitlab.com/handbook/engineering/ux/experience-baseline-recommendations/) [Experience Baselines and Recommendation: Release Q2](https://gitlab.com/groups/gitlab-org/-/epics/1326)
issue