Add proper favicon files for SEO and browser compatibility

- Create favicon.ico (multi-size: 16, 32, 48)
- Add favicon-16x16.png and favicon-32x32.png
- Add apple-touch-icon.png (180x180)
- Add android-chrome icons (192x192, 512x512)
- Add site.webmanifest for PWA support
- Update HTML with proper favicon link tags

Author: sin4ch

android-chrome-192x192.png

@@ -58,9 +58,13 @@
   <link rel="canonical" href="https://sin4.ch">
 
   <!-- Favicon -->
+  <link rel="icon" type="image/x-icon" href="/favicon.ico">
+  <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png">
+  <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png">
+  <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">
+  <link rel="manifest" href="/site.webmanifest">
+
   <title>Osinachi Okpara - AI Developer Advocate and Software Engineer</title>
-  <link rel="icon" id="favicon" type="image/png" href="profile-picture.png">
-  <link rel="apple-touch-icon" href="profile-picture.png">
   <link rel="preconnect" href="https://fonts.googleapis.com">
   <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
   <link href="https://fonts.googleapis.com/css2?family=Geist+Mono:wght@400;500;600&family=Instrument+Serif&display=swap" rel="stylesheet">

android-chrome-512x512.png

@@ -0,0 +1,19 @@
+{
+  "name": "Osinachi Okpara",
+  "short_name": "sin4.ch",
+  "icons": [
+    {
+      "src": "/android-chrome-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "/android-chrome-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }
+  ],
+  "theme_color": "#121212",
+  "background_color": "#121212",
+  "display": "standalone"
+}