Sync svelte docs (#1515)

sync svelte docs

Co-authored-by: svelte-docs-bot[bot] <196124396+svelte-docs-bot[bot]@users.noreply.github.com>

Author: github-actions[bot]

apps/svelte.dev/content/docs/svelte/07-misc/04-custom-elements.md

@@ -5,7 +5,7 @@ title: Custom elements
 
 <!-- - [basically what we have today](https://svelte.dev/docs/custom-elements-api) -->
 
-Svelte components can also be compiled to custom elements (aka web components) using the `customElement: true` compiler option. You should specify a tag name for the component using the `<svelte:options>` [element](svelte-options).
+Svelte components can also be compiled to custom elements (aka web components) using the `customElement: true` compiler option. You should specify a tag name for the component using the `<svelte:options>` [element](svelte-options). Within the custom element you can access the host element via the [`$host`](https://svelte.dev/docs/svelte/$host) rune.
 
 ```svelte
 <svelte:options customElement="my-element" />