src/main/options-normalizer.js/createRedirectOptionMessage
function createRedirectOptionMessage(optionInfo, descriptor) {
  return `${descriptor(
    optionInfo.name
  )} is deprecated. Prettier now treats it as ${
    typeof optionInfo.redirect === "string"
      ? descriptor(optionInfo.redirect)
      : descriptor(optionInfo.redirect.option, optionInfo.redirect.value)
  }.`;
}