Update list styles (#1) and further build out templates (#2).
- Add (currently blank) 404-content include
- Use `locale_date` instead of `date` for metadata
- Include 404 content if there are no articles in a rendered section for some reason (shouldn't happen)
- Add heading with either category or tag (as appropriate) to the corresponding templates
Paragraph styles and fix font-settings mixin (#1) and restructure meta content.