[JP] 07-routing/08-main.md not work

[ynishi]

Japanese 07-routing/08-main's code below has diff among others. https://github.com/sporto/elm-tutorial/blob/master/jp/07-routing/08-main.md

init : Result String Route -> ( Model, Cmd Msg )
init result =
    let
        currentRoute =
            Routing.routeFromResult result

urlUpdate result model =
    let
        currentRoute =
            Routing.routeFromResult result

Japanse code use routeFromResult, but in Route section, it is not implemented.

It is good to change same as en-v01. https://github.com/sporto/elm-tutorial/blob/master/en-v01/07-routing/08-main.md