document store bindings and $foo += 1

site/content/tutorial/08-stores/06-store-bindings/app-a/App.svelte

@@ -0,0 +1,6 @@
+<script>
+	import { name, greeting } from './stores.js';
+</script>
+
+<h1>{$greeting}</h1>
+<input value={$name}>

site/content/tutorial/08-stores/06-store-bindings/app-a/stores.js

@@ -0,0 +1,8 @@
+import { writable, derived } from 'svelte/store';
+
+export const name = writable('world');
+
+export const greeting = derived(
+	name,
+	$name => `Hello ${$name}!`
+);

site/content/tutorial/08-stores/06-store-bindings/app-b/App.svelte

@@ -0,0 +1,10 @@
+<script>
+	import { name, greeting } from './stores.js';
+</script>
+
+<h1>{$greeting}</h1>
+<input bind:value={$name}>
+
+<button on:click="{() => $name += '!'}">
+	Add exclamation mark!
+</button>

site/content/tutorial/08-stores/06-store-bindings/app-b/stores.js

@@ -0,0 +1,8 @@
+import { writable, derived } from 'svelte/store';
+
+export const name = writable('world');
+
+export const greeting = derived(
+	name,
+	$name => `Hello ${$name}!`
+);

site/content/tutorial/08-stores/06-store-bindings/text.md

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+---
+title: Store bindings
+---
+
+If a store is writable — i.e. it has a `set` method — you can bind to its value, just as you can bind to local component state.
+
+In this example we have a writable store `name` and a derived store `greeting`. Update the `<input>` element:
+
+```html
+<input bind:value={$name}>
+```
+
+Changing the input value will now update `name` and all its dependents.
+
+We can also assign directly to store values inside a component. Add a `<button>` element:
+
+```html
+<button on:click="{() => $name += '!'}">
+	Add exclamation mark!
+</button>
+```
+
+The `$name += '!'` assignment is equivalent to `name.set($name + '!')`.