Update image path to folder nested under dom-examples

[wesgarrison]

Old: https://mdn.github.io/to-do-notifications/img/icon-128.png
New: https://mdn.github.io/dom-examples/to-do-notifications/img/icon-128.png

[bsmth]

This is good for the GitHub version, but will break on local ones, should we do something like:

const basePath = window.origin.includes("github.io") 
  ? "/dom-examples" 
  : "";

const img = `${basePath}/to-do-notifications/img/icon-128.png`;

If it's on GitHub, add the repo to the base path, otherwise use an empty string?

[bsmth]

Thanks for opening this one, I think that's a good fix, there's one comment about running locally versus the preview, but I think we could even ignore my suggestion and add a note that this path should be changed in your local versions to get the icon to show. You can quickly test it with:

let local_notification = new Notification("To do list", {
  body: "Task text",
  icon: "/to-do-notifications/img/icon-128.png",
});

let gh_notification = new Notification("To do list", {
  body: "Task text",
  icon: "/dom-examples/to-do-notifications/img/icon-128.png",
});