fix(seo): correct OG image URL, fix homepage title, and add AI-friendly robots.txt

- Change og:image to absolute URL (https://33jsconcepts.com/og-image.png)
- Add thumbnails config and article:author to docs.json
- Fix homepage title from '33 JavaScript Concepts' to 'Learn JavaScript' to prevent duplication
- Create robots.txt allowing AI search engine bots (GPTBot, ClaudeBot, PerplexityBot)

Author: leonardomso

docs/docs.json

@@ -13,17 +13,21 @@
     "dark": "#C9B83C"
   },
   "favicon": "/favicon.ico",
+  "thumbnails": {
+    "appearance": "dark"
+  },
   "seo": {
     "indexing": "navigable",
     "metatags": {
       "og:type": "website",
       "og:site_name": "33 JavaScript Concepts",
       "og:locale": "en_US",
-      "og:image": "/og-image.png",
+      "og:image": "https://33jsconcepts.com/og-image.png",
       "twitter:card": "summary_large_image",
       "twitter:site": "@leonardomso",
       "twitter:creator": "@leonardomso",
       "twitter:image": "/og-image.png",
+      "article:author": "Leonardo Maldonado",
       "author": "Leonardo Maldonado",
       "keywords": "JavaScript, JS, learn JavaScript, JavaScript tutorial, JavaScript concepts, JavaScript fundamentals, web development, programming, coding, closures, promises, async await, event loop, DOM, prototypes",
       "language": "en",

docs/index.mdx

@@ -1,5 +1,5 @@
 ---
-title: "33 JavaScript Concepts"
+title: "Learn JavaScript"
 sidebarTitle: "Welcome"
 description: "Master JavaScript with 33 core concepts. Clear explanations, practical examples, and curated resources for developers at any level."
 ---

docs/robots.txt

@@ -0,0 +1,53 @@
+# Belt-and-suspenders robots.txt for 33jsconcepts.com
+# 
+# PRIMARY FIX: Cloudflare dashboard configuration is required to override
+# Cloudflare-managed AI bot blocking. This file serves as the origin-level
+# directive and fallback if Cloudflare managed robots is disabled.
+#
+# Cloudflare Dashboard Paths:
+# - Security -> Settings -> Bot traffic -> robots.txt setting
+# - AI Crawl Control -> Crawlers (allow/block per crawler)
+# - AI Crawl Control -> Robots.txt tab (check managed status)
+#
+# This file allows ALL major search engines and AI crawlers to index content.
+
+# Default rule: Allow all bots to crawl everything except Cloudflare internal paths
+User-agent: *
+Allow: /
+Disallow: /cdn-cgi/
+
+# Explicit allow directives for major search engine bots
+User-agent: Googlebot
+Allow: /
+
+User-agent: Bingbot
+Allow: /
+
+User-agent: Yandexbot
+Allow: /
+
+User-agent: DuckDuckBot
+Allow: /
+
+# Explicit allow directives for AI search engine bots
+# These override any Cloudflare-managed blocks at the origin level
+User-agent: GPTBot
+Allow: /
+
+User-agent: ChatGPT-User
+Allow: /
+
+User-agent: ClaudeBot
+Allow: /
+
+User-agent: anthropic-ai
+Allow: /
+
+User-agent: PerplexityBot
+Allow: /
+
+User-agent: Google-Extended
+Allow: /
+
+# Sitemap for search engine discovery
+Sitemap: https://33jsconcepts.com/sitemap.xml