fix: No undefined description

src/content/post/placeholder3.md

@@ -1,7 +1,6 @@
 ---
 title: Placeholder 3
 date: '2024-09-24'
-description: "This is a placeholder description"
 tags: []
 series: ["placeholder"]
 ---

src/lib/components/PostHeader.svelte

@@ -19,9 +19,11 @@
 			<a id="post-title" href="/post/{post.slug}">{post.title}</a>
 		{/if}
 	</h2>
+	{#if post?.description}
 		<div>
 			<p class="text-gray-500 h-8">{post.description}</p>
 		</div>
+	{/if}
 	<div class="flex flex-row justify-between" style="width: 100%">
 		<p class="text-gray-200 flex justify-center">
 			{#each (post?.tags ?? []) as tag, i}