Subforum index: row layout instead of tiles
Fix timestamp in subforum view
Turn top border for subforums on index into a div
Add descriptions to subforums
Better new posts labels on subforum index
Redesigned index subforum header info
More awesomeness on the front page
Quick subforum links at top of index
Slightly better mobile index
Use `open { |f| block }` form

This guaranteees `f.close` get's called. No idea if it's necessary for
open-uri, but it's better to be safe.
Auto subscribe new HSers to New York subforum.
Also subscribe current HSers to "455 Broadway"
Font size tweaks
Hide breadcrumbs on mobile
Better subforum index quick links on mobile
Various tweaks to subforum index mobile view
Remove unnecessary subscription (not showing on index)
Extract subforum info into its own component
Extract subforum-info styles
Move subforum info styles into other file