optimize "Pull Quote"

- move variables to partial
- use `aside` instead of `blockquote`
- use `quotes` instead of `content`
- add styles for small/medium screen
Increase "Pull Quote" width
Make "Pull Quote" quotes bolder
Add comment
Rebuild "Chain" image
Use `%ir` for "Seealso"
Fix "Social Buttons" margins on small screen
Place "Article Footer" before "Section Header"
Fix right margin of "Site Navigation" last item
version 6.43.13