Update svelte and typescript usage

src/lib/Thumbnail.svelte

@@ -1,9 +1,19 @@
 <script lang="ts">
-    export let name: string;
-    export let link: string;
-    export let img = "https://placehold.it/600x300";
-    export let size = { width: 600, height: 300 };
-    export let description: string;
+    interface Props {
+        name: string;
+        link: string;
+        img?: string;
+        size?: { width: number; height: number };
+        description: string;
+    }
+
+    let {
+        name,
+        link,
+        img = "https://placehold.it/600x300",
+        size = { width: 600, height: 300 },
+        description
+    }: Props = $props();
 </script>
 
 <div class="card">