bobatheme: Various CSS cleanup and small UI tweaks

- Rename list.html to taxonomy.html in authors and series
- Use specific class for website footer instead of generic tag selector
- Improve semantic HTML tag usage on content pages
- Only show hr on home if homepageLatestPosts enabled
- Put title on series page in div.page-title like other taxonomy pages
- Use hierarchical naming on top and its elements
- Remove nested list-page-container to simplify layout CSS on section
  page
- Add arrow in the right side of list page section buttons
- Remove leftover additional-head partial
- Use section tag for homepage latest posts section
- Move article.page wrapping to summary.html instead of at list template
- Move summary card CSS to a new fold section
- Rename summary card classes from .page to .summary-card
- Rename feature-figure.html to featured-media and combine CSS with
  figures
- Reorganize series page list and series summary card class names
- Change "Read more" to "See posts" on author summary card
- Merge branch 'page-list-and-summary-css-cleanup'

Author: BBaoVanC