Add SEO improvements for worknot.classmethod.live

- Add favicon.svg with Worknot branding
- Add og-image.svg for social media sharing (1200x630)
- Add robots.txt with sitemap reference
- Add sitemap.xml for search engine indexing
- Add og:image, og:image:width, og:image:height meta tags
- Add og:locale meta tag (en_US)
- Add twitter:image meta tag
- Add JSON-LD structured data (WebApplication schema)

Closes #47 (Phase 1 and Phase 2 items)

Author: shigahi

index.html

@@ -8,6 +8,10 @@
         />
         <meta name="theme-color" content="#1976d2" />
 
+        <!-- Favicon -->
+        <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+        <link rel="apple-touch-icon" href="/favicon.svg" />
+
         <!-- SEO Meta Tags -->
         <title>
             Worknot - Host Notion Sites on Your Custom Domain | Cloudflare
@@ -35,6 +39,13 @@
             content="Host your Notion Site on a custom domain with Cloudflare Workers. Actively maintained by Classmethod, always up-to-date with the latest Notion specifications."
         />
         <meta property="og:site_name" content="Worknot" />
+        <meta
+            property="og:image"
+            content="https://worknot.classmethod.live/og-image.svg"
+        />
+        <meta property="og:image:width" content="1200" />
+        <meta property="og:image:height" content="630" />
+        <meta property="og:locale" content="en_US" />
 
         <!-- Twitter -->
         <meta name="twitter:card" content="summary_large_image" />
@@ -47,10 +58,37 @@
             name="twitter:description"
             content="Host your Notion Site on a custom domain with Cloudflare Workers. Actively maintained by Classmethod, always up-to-date with the latest Notion specifications."
         />
+        <meta
+            name="twitter:image"
+            content="https://worknot.classmethod.live/og-image.svg"
+        />
 
         <!-- Canonical URL -->
         <link rel="canonical" href="https://worknot.classmethod.live/" />
 
+        <!-- Structured Data (JSON-LD) -->
+        <script type="application/ld+json">
+            {
+                "@context": "https://schema.org",
+                "@type": "WebApplication",
+                "name": "Worknot",
+                "description": "Host your Notion Site on a custom domain with Cloudflare Workers. Generate Worker scripts to proxy Notion pages with pretty URLs and image optimization.",
+                "url": "https://worknot.classmethod.live/",
+                "applicationCategory": "DeveloperApplication",
+                "operatingSystem": "Web",
+                "offers": {
+                    "@type": "Offer",
+                    "price": "0",
+                    "priceCurrency": "USD"
+                },
+                "creator": {
+                    "@type": "Organization",
+                    "name": "Classmethod",
+                    "url": "https://classmethod.jp/"
+                }
+            }
+        </script>
+
         <!-- Fonts -->
         <link rel="preconnect" href="https://fonts.googleapis.com" />
         <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />

public/favicon.svg

@@ -0,0 +1,4 @@
+User-agent: *
+Allow: /
+
+Sitemap: https://worknot.classmethod.live/sitemap.xml

public/og-image.svg

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+  <url>
+    <loc>https://worknot.classmethod.live/</loc>
+    <changefreq>weekly</changefreq>
+    <priority>1.0</priority>
+  </url>
+</urlset>