Fixed misleading comment

src/routes/blog/[slug].svelte

@@ -1,7 +1,7 @@
 <script context="module">
 	export async function preload({ params, query }) {
 		// the `slug` parameter is available because
-		// this file is called [slug].html
+		// this file is called [slug].svelte
 		const res = await this.fetch(`blog/${params.slug}.json`);
 		const data = await res.json();
 
@@ -61,4 +61,4 @@
 
 <div class='content'>
 	{@html post.html}
-</div>
+</div>