Add SlugNotFound component and update en.json for news page

app/[locale]/news/[slug]/not-found.tsx

@@ -0,0 +1,21 @@
+import Link from "next/link";
+import { useTranslations } from "next-intl";
+
+export default function SlugNotFound() {
+  const t = useTranslations("news.notFound");
+
+  return (
+    <div className="pt-10 pb-24 sm:pt-12 sm:pb-32">
+      <div className="mx-auto max-w-3xl text-base leading-7">
+        <h1 className="mt-2 text-3xl font-bold tracking-tight sm:text-4xl mb-12 text-center font-display">
+          {t("title")}
+        </h1>
+        <div className="prose dark:prose-invert prose-headings:font-display prose-a:text-primary prose-pre:bg-muted prose-pre:py-3 prose-pre:px-4 prose-pre:rounded prose-img:rounded-md max-w-none">
+          {t.rich("description", {
+            newsLink: (chunks) => <Link href="/news">{chunks}</Link>,
+          })}
+        </div>
+      </div>
+    </div>
+  );
+}

messages/en.json

@@ -66,5 +66,11 @@
         "description": "Migrate from other Enterprise Linux distributions without sweating it. We provide an easy-to-use migration script, free of charge."
       }
     }
+  },
+  "news": {
+    "notFound": {
+      "title": "Not Found",
+      "description": "The news post you are looking for does not exist. You can find all our news posts on the <newsLink>news page</newsLink>."
+    }
   }
 }