Type definition of `fields` in TransformedData may be mistake

[yeongjet]

winston-elasticsearch/index.d.ts

Line 55 in d948fa1

fields: string

while using transformer:

new ElasticsearchTransport(
  ...
  transformer: logData => {
      const transformed = ElasticsearchTransformer(logData)
      const requestId = this.cls.get('requestId')
      if (requestId) {
          // ERROR: Property 'requestId' does not exist on type 'string'.ts(2339)
          transformed.fields.requestId = requestId
      }
      return transformed
  }
}