Update _index.md

Author: cabbetlong

content/en/docs/_index.md

@@ -7,6 +7,6 @@ weight: 20
 
 You can get the PDF version of the user guide from the following link：
 
-<a class="btn btn-lg btn-secondary me-3 mb-4" href="https://github.com/Huawei/eSDK_K8S_Plugin/blob/v4.10.0/docs/eSDK%20Huawei%20Storage%20Kubernetes%20CSI%20Plugins%20V4.10.0%20User%20Guide%2001.pdf">
+<a class="btn btn-lg btn-secondary me-3 mb-4" href="https://github.com/Huawei/eSDK_K8S_Plugin/blob/master/docs/eSDK%20Huawei%20Storage%20Kubernetes%20CSI%20Plugins%20V4.10.0%20User%20Guide%2001.pdf">
   PDF Download <i class="fa-solid fa-file-pdf"></i>
 </a>