Add support for Uint8(Clamped)Array input (#2511)

lib/output.js

@@ -104,6 +104,20 @@ function toFile (fileOut, callback) {
  *   .then(({ data, info }) => { ... })
  *   .catch(err => { ... });
  *
+ * @example
+ * const data = await sharp('my-image.jpg')
+ *   // output the raw pixels
+ *   .raw()
+ *   .toBuffer();
+ *
+ * // create a more type safe way to work with the raw pixel data
+ * // this will not copy the data, instead it will change `data`s underlying ArrayBuffer
+ * // so `data` and `pixelArray` point to the same memory location
+ * const pixelArray = new Uint8ClampedArray(data.buffer);
+ *
+ * // When you are done changing the pixelArray, sharp takes the `pixelArray` as an input
+ * await sharp(pixelArray).toFile('my-changed-image.jpg');
+ *
  * @param {Object} [options]
  * @param {boolean} [options.resolveWithObject] Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
  * @param {Function} [callback]