fix: correct <meta> property casing (#1455)

Co-authored-by: Tee Ming <[email protected]>

Author: Ocean-OS

apps/svelte.dev/src/routes/(authed)/playground/[id]/+page.svelte

@@ -179,7 +179,7 @@
 
 	<meta name="twitter:title" content="{data.gist.name} • Playground • Svelte" />
 	<meta name="twitter:description" content="Web development for the rest of us" />
-	<meta name="Description" content="Interactive Svelte playground" />
+	<meta name="description" content="Interactive Svelte playground" />
 </svelte:head>
 
 <svelte:window

apps/svelte.dev/src/routes/(authed)/playground/[id]/embed/+page.svelte

@@ -59,7 +59,7 @@
 
 	<meta name="twitter:title" content="{data.gist.name} • Playground • Svelte" />
 	<meta name="twitter:description" content="Web development for the rest of us" />
-	<meta name="Description" content="Interactive Svelte playground" />
+	<meta name="description" content="Interactive Svelte playground" />
 </svelte:head>
 
 <div class="repl-outer">

apps/svelte.dev/src/routes/+page.svelte

@@ -14,7 +14,7 @@
 
 	<meta name="twitter:title" content="Svelte" />
 	<meta name="twitter:description" content="Web development for the rest of us" />
-	<meta name="Description" content="Web development for the rest of us" />
+	<meta name="description" content="Web development for the rest of us" />
 </svelte:head>
 
 <div class="home">

apps/svelte.dev/src/routes/blog/+page.svelte

@@ -19,7 +19,7 @@
 
 	<meta name="twitter:title" content="Svelte blog" />
 	<meta name="twitter:description" content="Articles about Svelte and UI development" />
-	<meta name="Description" content="Articles about Svelte and UI development" />
+	<meta name="description" content="Articles about Svelte and UI development" />
 </svelte:head>
 
 <h1 class="visually-hidden">Blog</h1>

apps/svelte.dev/src/routes/blog/[slug]/+page.svelte

@@ -15,7 +15,7 @@
 	<meta name="twitter:card" content="summary_large_image" />
 	<meta name="twitter:title" content={data.metadata.title} />
 	<meta name="twitter:description" content={data.metadata.description} />
-	<meta name="Description" content={data.metadata.description} />
+	<meta name="description" content={data.metadata.description} />
 
 	<meta name="twitter:image" content="https://svelte.dev/blog/{$page.params.slug}/card.png" />
 	<meta name="og:image" content="https://svelte.dev/blog/{$page.params.slug}/card.png" />

apps/svelte.dev/src/routes/docs/[topic]/[...path]/+page.svelte

@@ -66,7 +66,7 @@
 		content="{data.document.metadata.title} • Svelte documentation"
 	/>
 	<meta name="twitter:card" content="summary_large_image" />
-	<meta name="Description" content="{data.document.metadata.title} • Svelte documentation" />
+	<meta name="description" content="{data.document.metadata.title} • Svelte documentation" />
 	<meta
 		name="twitter:image"
 		content="https://svelte.dev/docs/{page.params.topic}/{page.params.path}/card.png"