a11y: Items in the feature list aren't focusable.

[mikewest]

Tabbing through the document should eventually land me on the clickable feature list. It currently doesn't, as each item is just a flat <div>. I'd suggest adding "tabindex='0'" to each element that you expect folks to interact with (or changing them to use something which is natively focusable, like <a> or <button>).

As a second step, it would be good to ensure that they're interactwithable (yes, that's a word now) via the keyboard. :)

Thanks!

-mike

[ebidel]

Tab index fixed in: f2b9518.

Fixed a separate issue for keyboard nav: #49