Update open-collective contributors badge (#329)

Author: DefTruth

README.md

@@ -30,7 +30,7 @@
 <div align="center">
   <p align="center">
     <a href="#contribute">🔥🔥 PR Welcome: Add Your Kernel to LeetCUDA! Let's make it Awesome together! 🎉🎉</a>
-    <img src=https://opencollective.com/leetcuda/contributors.svg>
+    <a href=https://github.com/xlite-dev/LeetCUDA/graphs/contributors > <img src=https://opencollective.com/leetcuda/contributors.svg height=40px > </a>
   </p>
 </div>