Add the "elm-format path" in the settings of the plugin

[lucamug]

I run several Elm project and I have all dependencies installed inside the project, including elm-format.

It would be great if I could tell atom-elm-format to use the local installation.

Similar to how elmjutsu allow to specify the path of elm binary.

[rhoskal]

@lucamug I believe this is already done. Atom -> Preferences -> Packages -> elm-format -> settings