**Please do not work on this issue unless you have applied to the outreachy project.**

The [jpeg_viewer.js](https://github.com/mozilla/pdf.js/blob/master/examples/image_decoders/jpeg_viewer.js) example currently uses the older style of `promise.then` and callbacks. Convert it to use an `async` function and `await` style.

* Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
"use strict";
if (!pdfjsImageDecoders.JpegImage) {
  
  alert("Please build the pdfjs-dist library using `gulp dist-install`");
}
const JPEG_IMAGE = "fish.jpg";
const jpegCanvas = document.getElementById("jpegCanvas");
const jpegCtx = jpegCanvas.getContext("2d");
let nonBinaryRequest = false;
const request = new XMLHttpRequest();
request.open("GET", JPEG_IMAGE, false);
try {
  request.responseType = "arraybuffer";
  nonBinaryRequest = request.responseType !== "arraybuffer";
} catch (e) {
  nonBinaryRequest = true;
}
if (nonBinaryRequest && request.overrideMimeType) {
  request.overrideMimeType("text/plain; charset=x-user-defined");
}
request.send(null);
let typedArrayImage;
if (nonBinaryRequest) {
  const str = request.responseText,