Disable range formatting

[Skarvion]

Hi, I'm using a custom formatter for a niche language, which does not support range formatting correctly.

Can you please allow an option to disable range formatting for particular languages?

[zaneduffield]

The approach implemented in version 0.2.0 hardly makes sense for most formatters.

By only sending a subset of a document to a formatter, how can you expect to get valid formatting for that subset? The original issue requesting this feature (#15) alluded to this

I think this may require adding the option to not pass the code via stdin (and instead via filename and line numbers)

All formatters that I know of with first-class support for formatting ranges implement it in this kind of way, where the whole document is provided as input, and the selection to format is specified in some other way.

If the strategy implemented here actually works properly for some formatters (which I struggle to imagine), then maybe there's an argument for keeping range formatting on an opt-in basis, but there's no world where this feature should be enabled by default.