add initial demo app

src/app/.well-known/frames.json/route.ts

@@ -0,0 +1,19 @@
+export async function GET() {
+  const appUrl = process.env.NEXT_PUBLIC_URL;
+
+  const config = {
+    config: {
+      version: "0.0.0",
+      name: "Frames v2 Demo",
+      icon: `${appUrl}/icon.png`,
+      splashImage: `${appUrl}/splash.png`,
+      splashBackgroundColor: "#f7f7f7",
+      homeUrl: appUrl,
+      fid: 0,
+      key: "",
+      signature: "",
+    },
+  };
+
+  return Response.json(config);
+}