HN Keyboard Boost by Jesse Soo

HN Keyboard Boost adds lightweight keyboard navigation to Hacker News.

Browse stories and comments without leaving the keyboard:
- j / k: next / previous item
- h / l: parent / child comment
- J / K: next / previous sibling comment
- [ / ]: previous / next top-level thread
- x: collapse / expand comments
- o: open story or comments
- c: open comments
- r: reply
- v: upvote
- m: next page
- ?: show help