Add SVG assets and TypeScript configuration

- Created a new SVG for the Open Graph image (og-image.svg) with a gradient background and text elements.
- Added Vercel logo SVG (vercel.svg) for deployment branding.
- Introduced a window icon SVG (window.svg) for UI representation.
- Initialized TypeScript configuration file (tsconfig.json) with strict settings and module resolution for a React project.

public/manifest.json

@@ -0,0 +1,26 @@
+{
+  "name": "BlocNote — Bloc-notes Markdown en ligne",
+  "short_name": "BlocNote",
+  "description": "Bloc-notes en ligne moderne avec support Markdown, sauvegarde automatique et mode sombre.",
+  "start_url": "/",
+  "display": "standalone",
+  "orientation": "any",
+  "background_color": "#ffffff",
+  "theme_color": "#3b82f6",
+  "lang": "fr",
+  "categories": ["productivity", "utilities"],
+  "icons": [
+    {
+      "src": "/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }
+  ]
+}