Support for app.config files

[Shmew]

It would be really awesome if we could use this in combination with something like FSharp.Configuration. Do you have plans for any further functionality?

[Tarmil]

I'm definitely open to more functionality!

App.config is normally meant for runtime configuration, so this would probably have much more limited use than FSharp.Configuration, but I guess it can still be useful.

[Shmew]

JSON/YAML works too, just something a bit more refined than a text file I think would be a great feature.

[endeavour]

+1. Would be great if you could use this to pull individual values out of a json and/or yaml file.