feat(web): onboarding wizard (MS22-P1f) (#616)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/web/src/app/onboarding/layout.tsx

@@ -0,0 +1,9 @@
+import type { ReactNode } from "react";
+
+export default function OnboardingLayout({ children }: { children: ReactNode }): React.JSX.Element {
+  return (
+    <main className="flex min-h-screen items-center justify-center bg-gradient-to-b from-slate-50 to-white p-4 sm:p-6">
+      <div className="w-full max-w-3xl">{children}</div>
+    </main>
+  );
+}