Minor bug at the comment section of the 'oneOf' function

```elm
{-

    route : Parser (Route -> a) a
    route =
      oneOf
        [ map Search  (s "search" </> string)
        , map Blog    (s "blog" </> int)
        , map User    (s "user" </> string)
        , map Comment (s "user" </> string </> "comments" </> int)
        ]

-}
```

The `s` function call is missing at `map Comment (s "user" </> string </> s "comments" </> int)`