Add keyboard navigation about hackerweb

[sbdchd]

I made a basic implementation of keyboard navigation, which works for the main page (not the comments).

See here.

Suggestions are much appreciated.

Keyboard Nav
j - move down
k - move up

o - open story
c - open comments page

<backspace> - go to previous page (this is just normal browser behavior)

[cheeaun]

@sbdchd wow, that's really cool! I think you need e.preventDefault for the key presses, I enabled 'Search for text when I start typing' on my Firefox 😛

I'll further look at this during the weekend and see what I can do.

[sbdchd]

There seems to be an issue with this setup triggering more.

Sometimes, after more is triggered, the posts will become duplicated on the page.

In this case, the page will add on the items 31-60 multiple times to the current 1-30 posts.

When triggering more by hand this doesn't happen.