Add structure to admin area page
What does this MR do?
As #57874 (closed) is built out, we need to start making use of more structure.
This MR implements a simple structure that should scale for a while (while everything is maintained in a single page).
- Follow the Documentation Guidelines and Style Guide.
- Link docs to and from the higher-level index page, plus other related docs where helpful.
- Apply the Documentation label.
1. Primary Reviewer
- Review by a code reviewer or other selected colleague to confirm accuracy, clarity, and completeness. This can be skipped for minor fixes without substantive content changes.
2. Technical Writer
- Optional: Technical writer review. If not requested for this MR, must be scheduled post-merge. To request for this MR, assign the writer listed for the applicable DevOps stage.
- Review by assigned maintainer, who can always request/require the above reviews. Maintainer's review can occur before or after a technical writer review.
- Ensure a release milestone is set and that you merge the equivalent EE MR before the CE MR if both exist.
- If there has not been a technical writer review, create an issue for one using the Doc Review template.