Include elm-hot-loader

[Dima Utkin]

Hi Peter,

it would be really great to include elm-hot-loader into the starter kit. I've just spent about an hour tying all the things together. I could make a PR, but I'm not that profound in Elm so far and all the nuances of StartApp(example in elm-hot-loader repo) vs StartApp.Simple.

Thanks for your work!

[Peter Morawiec]

@gothy: Done. Your friend @fluxxu was kind enough to do the PR. :)