When this is done the hab docs will have
- Subdirectories for each "main topic"
- Each subdirectory has files from the original doc's h2
- Each subdirectory has a main topic page and is correctly wired into the sidebar
- Each file is named from the origin h2's id field
- Each file has a title from the original section title
- Each file has properly-formed frontmatter
- Each file is wired into the sidebar
- Remove TOC's
- Remove Magellan lines
- Conform Markdown heading levels