feat: update examples page with SDK examples, fix API URLs

- Node.js and Python examples now show SDK usage (recommended) + raw HTTP
- Fix api.docfast.dev → docfast.dev in all curl examples
- Update features subtitle to mention official SDKs

public/index.html

@@ -402,7 +402,7 @@ html, body {
 <section class="features" id="features">
   <div class="container">
     <h2 class="section-title">Everything you need</h2>
-    <p class="section-sub">A complete PDF generation API. No SDKs, no dependencies, no setup.</p>
+    <p class="section-sub">A complete PDF generation API. Official SDKs for Node.js &amp; Python, or just use curl.</p>
     <div class="features-grid">
       <div class="feature-card">
         <div class="feature-icon" aria-hidden="true">⚡</div>