support package.json exports["."].svelte

[hatemhosny]

Assuming we are in a svelte component and want to import other svelte components in a published package.
It would be nice if esm.sh can use the svelte entry of exports

{
	"exports": {
		".": {
			"types": "./dist/index.d.ts",
			"svelte": "./dist/index.js"
		}
	}
// ...
}

example: https://app.unpkg.com/@onsvisual/svelte-components@1.0.30/files/package.json#L35

To allow usage like this:
https://onsdigital.github.io/svelte-components/?path=/docs/introduction--docs#using-the-components

<!-- +layout.svelte -->
<script>
  import "@onsvisual/svelte-components/css/main.css";
</script>

<slot/>

<!-- +page.svelte / Component.svelte -->
<script>
  import { Section } from "@onsvisual/svelte-components";
</script>

<Section title="Hello world!">I am using an ONS Svelte component.</Section>