feat(site): link the CPU engineering-samples catalog from the footer

Refs #19

Author: Seungpyo1007

site/src/pages/index.astro

@@ -331,6 +331,7 @@ const endpoints = [
           <a href={ghUrl} target="_blank" rel="noopener">GitHub</a>
           <a href={`${base}docs`}>API reference</a>
           <a href="#playground">Playground</a>
+          <a href="https://gettechapi.github.io/cpu-engineering-samples/" target="_blank" rel="noopener">CPU engineering samples</a>
         </div>
       </div>
       <p class="foot-warn">⚠ Curated, growing dataset — not yet an exhaustive catalog of every device.</p>