add NCB into friendly link

Author: ganler

leaderboard.html

@@ -253,6 +253,9 @@ <h3>🤗 More Leaderboards</h3>
                 >LiveCodeBench</a
               >
             </li>
+            <li>
+              <a href="https://github.com/THUDM/NaturalCodeBench">NaturalCodeBench</a>
+            </li>
             <li><a href="https://github.com/Leolty/repobench">RepoBench</a></li>
             <li><a href="https://www.swebench.com/">SWE-bench</a></li>
             <li>