adding button to sourcebench post

Author: yiying-zhang

layouts/shortcodes/sourcebench/checkout-paper.html

@@ -0,0 +1,9 @@
+<div class="p-4 flex w-full items-center justify-center text-center">
+  <a href="https://arxiv.org/abs/2602.16942" target="_blank" rel="noopener noreferrer" class="no-underline">
+    <button
+      class="bg-blue-500 text-white py-4 px-8 border-0 rounded-lg text-lg font-sans cursor-pointer inline-block text-center transition-colors duration-300 hover:bg-blue-700"
+    >
+      <strong style="color: white;">Read Full Paper</strong>
+    </button>
+  </a>
+</div>