partial fix

site/content/examples/hello-world/App.html

@@ -7,8 +7,8 @@ below right to see the generated code.
 You can interact with this component via your
 browser's console - try running the following:
 
-    app.set({ name: 'everybody' });
+    app.name = 'everybody';
 
-You can also update the data via the JSON
+You can also update the data via the props
 editor on this page.
 -->

site/content/examples/immutable/ImmutableTodo.html

@@ -1,19 +1,15 @@
 <svelte:meta immutable/>
 
 <script>
-	import { afterRender } from 'svelte';
+	import { afterUpdate } from 'svelte';
+	import flash from './flash.js';
 
 	export let todo;
 	let span;
 
-	afterRender(() => {
-		span.style.color = 'red';
-		setTimeout(() => {
-			span.style.color = 'black';
-		}, 400);
-	});
+	flash(() => span);
 </script>
 
 <!-- the text will flash red whenever
      the `todo` object changes -->
-<span ref:span>{todo.text}</span>
+<span bind:this={span}>{todo.text}</span>

site/content/examples/immutable/MutableTodo.html

@@ -1,17 +1,13 @@
 <script>
-	import { afterRender } from 'svelte';
+	import { afterUpdate } from 'svelte';
+	import flash from './flash.js';
 
 	export let todo;
 	let span;
 
-	afterRender(() => {
-		span.style.color = 'red';
-		setTimeout(() => {
-			span.style.color = 'black';
-		}, 400);
-	});
+	flash(() => span);
 </script>
 
 <!-- the text will flash red whenever
      the `todo` object changes -->
-<span ref:span>{todo.text}</span>
+<span bind:this={span}>{todo.text}</span>

site/content/examples/immutable/flash.js

@@ -0,0 +1,13 @@
+import { afterUpdate } from 'svelte';
+
+export default function flash(fn) {
+	afterUpdate(() => {
+		const span = fn();
+
+		span.style.color = 'red';
+
+		setTimeout(() => {
+			span.style.color = 'black';
+		}, 400);
+	});
+}