Feat/add manifest.ts (#270)

* Add manifest file for Next AI Draw.io application

This file defines the manifest for the Next AI Draw.io application, including metadata like name, description, and icons.

* Add different sizes of favicon

* Update app/manifest.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update app/manifest.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Dayuan Jiang <34411969+DayuanJiang@users.noreply.github.com>

app/manifest.ts

@@ -0,0 +1,27 @@
+import type { MetadataRoute } from "next";
+
+export default function manifest(): MetadataRoute.Manifest {
+  return {
+    name: 'Next AI Draw.io',
+    short_name: 'AIDraw.io',
+    description: 'Create AWS architecture diagrams, flowcharts, and technical diagrams using AI. Free online tool integrating draw.io with AI assistance for professional diagram creation.',
+    start_url: '/',
+    display: 'standalone',
+    background_color: '#f9fafb',
+    theme_color: '#171d26',
+    icons: [
+      {
+        src: '/favicon-192x192.png',
+        sizes: '192x192',
+        type: 'image/png',
+        purpose: 'any',
+      },
+      {
+        src: '/favicon-512x512.png',
+        sizes: '512x512',
+        type: 'image/png',
+        purpose: 'any',
+      },
+    ],
+  }
+}