Ability to customize Fantomas code formatting options

[johlrich]

The default settings are being used at the moment. We should consider adding the ability to configure the settings used.

Ideally this would be done in a way that can be overridden per repository.

Some comments from #editor_support slack thread that led to this isssue:

"It would be cool if Fantomas had some kind of settings.json files that we could load instead of adding all options to the Ionide's settings"

"yeah that would be great, then you could also run it in your build as an enforcement step and keep it consistent."

[johlrich]

Related issue in fantomas: fsprojects/fantomas#354

[Krzysztof-Cieslak]

This is done now.

[cmeeren]

Great that FSAC/Fantomas respects a repo-level config file now! Is it possible to specify a machine-wide default config (where values will be overridden by a repo-level config file)?