Hot reloading

[hickscorp]

Please note that this is absolutely not an issue, more an enhancement request, so feel free to close it.

I'm completely new to Elm and I have tried to understand how to have hot module reloading as an addition of this repository.

BTW this repo was by far the best for me to understand how all the bits and pieces go together, so thanks for that 👍. I've spent some time adapting this to a Phoenix 1.3 project and it worked like a charm.

I think it would be nice to add a hot reload option and explain the commit that adds it, as there are so many contradictory sources around that it's a nightmare (on Elm street) to pick what's good, so having this here would be really great.

I tried with webpack-combine-loaders by having a elm-hot loader and elm-webpack loader combined, but I ended up having my full page reloaded anyway.