Added simple index page w/ hiccup

What do you think of embedding the index page like this? I'm guessing we'll be fetching a bit of data here and incorporating it in the output (like latest submissions).
`use` is deprecated in favour of `refer`. So this should be:

```clojure
(:require [hiccup.page :refer :all])
```

or better still, add it to the existing requires. Also, if it isn't too long of a list, better to `:refer [html5]` (for example).