Improve documentation for FormDataEncoder constructor.

Author: octet-stream

src/FormDataEncoder.ts

@@ -91,6 +91,7 @@ export class FormDataEncoder {
    *
    * @example
    *
+   * ```js
    * import {Readable} from "stream"
    *
    * import {FormData, File, fileFromPath} from "formdata-node"
@@ -115,9 +116,24 @@ export class FormDataEncoder {
    * const response = await fetch("https://httpbin.org/post", options)
    *
    * console.log(await response.json())
+   * ```
    */
   constructor(form: FormDataLike)
+
+  /**
+   * Creates multipart/form-data encoder with custom boundary string.
+   *
+   * @param form FormData object to encode. This object must be a spec-compatible FormData implementation.
+   * @param boundary An optional boundary string that will be used by the encoder. If there's no boundary string is present, Encoder will generate it automatically.
+   */
   constructor(form: FormDataLike, boundary: string)
+
+  /**
+   * Creates multipart/form-data encoder with additional options.
+   *
+   * @param form FormData object to encode. This object must be a spec-compatible FormData implementation.
+   * @param options Additional options
+   */
   constructor(form: FormDataLike, options: FormDataEncoderOptions)
   constructor(
     form: FormDataLike,