docs: add step for adding font links in svelte:head to sveltekit installation guide (#67)

* docs: add step for adding font links in svelte:head to sveltekit installation guide

* style: replace tabs with spaces

Author: Mef45

README.md

@@ -129,6 +129,17 @@ export default defineConfig({
     })
   ]
 })
+
+// +layout.svelte
+<script>
+  import { links } from 'unplugin-fonts/head'
+</script>
+
+<svelte:head>
+  {#each links as link}
+    <link {...link?.attrs || {}} />
+  {/each}
+</svelte:head>
 ```
 
 Example: [`examples/sveltekit`](./examples/sveltekit)