Begin SEO and accessibility optimizations

src/routes/+layout.svelte

@@ -1,5 +1,11 @@
 <script lang="ts">
+  import { page } from '$app/stores';
   import "$lib/styles/base.css";
 </script>
 
+<svelte:head>
+  <title>{$page.data.title || 'Galerie'} | bosin.ch</title>
+  <meta name="description" content={$page.data.description || 'Fotogalerie von Luca Bosin'} />
+</svelte:head>
+
 <slot />