feat(webapp): added a 404 page. (#39)

apps/snakecode-webapp/src/pages/404.tsx

@@ -0,0 +1,22 @@
+import Link from "next/link";
+
+import Navbar from "@/components/common/navbar";
+import routes from "@/constants/routes";
+import Banner from "@/components/common/banner";
+
+export default function Custom404() {
+  return (
+    <div className="flex h-screen flex-col bg-bg">
+      <Navbar />
+
+      <main className="flex h-full w-full flex-col items-center justify-center font-sans text-pt">
+        <span className="-mt-24 text-pc text-center font-sans font-extrabold text-2xl tracking-wide sm:text-2xl">
+          404
+        </span>
+        <span className="mt-4 font-display text-5xl">Oh, hello!</span>
+        <span className="mt-4 text-st font-sans font-bold text-xl">Looks like you might have gotten <span className="text-pc">a bit lost</span></span>
+        <Link className="mt-10 font-black text-red text-lg" href={routes.root}>START HERE</Link>
+      </main>
+    </div>
+  );
+}