simplify Canvas.svelte in actions tutorial

[Rich-Harris]

small thing i noticed

[Hugos68]

Isn't it even simpler and more modular to use on?

$effect(() => on(window, 'resize' () => {
    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
}));

[Rich-Harris]

No, because that won't result in the function being called when the component first mounts