It's only the documentation that's a TODO, you can use them currently. Just pass `customElements: true` to the compiler and specify a tag, either as `tag: 'my-t

It's only the documentation that's a TODO, you can use them currently. Just pass `customElements: true` to the compiler and specify a tag, either as `tag: 'my-tag'` or in the component itself with `<svelte:options tag="my-tag"/>`. TODO: make shadow DOM optional, and only auto-register if a tag is provided (currently it's required)