chore: add appDir edge page to default demo

Author: ascorbic

demos/default/app/app-edge/layout.tsx

@@ -0,0 +1,11 @@
+'use client'
+
+// TODO-APP: support typing for useSelectedLayoutSegment
+// @ts-ignore
+import { useSelectedLayoutSegments } from 'next/navigation'
+
+export default function Layout({ children }: { children: React.ReactNode }) {
+  // useSelectedLayoutSegment should not be thrown
+  useSelectedLayoutSegments()
+  return children
+}

demos/default/app/app-edge/page.tsx

@@ -0,0 +1,8 @@
+export default function Page() {
+  if ('EdgeRuntime' in globalThis) {
+    return <p>Edge!</p>
+  }
+  return <p>Node!</p>
+}
+
+export const runtime = 'experimental-edge'