refmt makes record fields with `bs` annotations harder to read

[mlms13]

This is purely subjective, so feel free to close if you disagree, but it bothered me enough that I thought I'd mention it. :smile: The following code:

[@bs.deriving abstract]
type t = {
  [@bs.optional] filename: string,
  [@bs.optional] onWarning: Js.Exn.t => unit,
  [@bs.optional] schema: schema,
  [@bs.optional] json: bool,
};

gets turned into:

[@bs.deriving abstract]
type t = {
  [@bs.optional]
  filename: string,
  [@bs.optional]
  onWarning: Js.Exn.t => unit,
  [@bs.optional]
  schema,
  [@bs.optional]
  json: bool,
};

after refmt works its magic. The refmt'd version is inconsistent with the formatting used in the bucklescript object docs, and in my opinion it's substantially harder to make sense of.