Fix link format

Author: jondy

www/index-zh.html

@@ -251,7 +251,7 @@ <h3 class="text-info">更多用法请阅读入门教程 <a class="btn btn-outlin
         <div class="col-12 col-md-6 col-lg-4">
           <h2 class="text-info">更多资源</h2>
           <div class="list-group list-group-flush border-bottom mt-3">
-            <a class="nav-link" href="https://eke.dashingsoft.com/pyarmor/" target="_pyarmordoc">学习和提问</a>
+            <a href="https://eke.dashingsoft.com/pyarmor/" target="_pyarmordoc" class="list-group-item list-group-item-action text-info bg-light">学习和提问</a>
             <a href="https://pyarmor.readthedocs.io/zh/latest/" target="_pyarmordoc" class="list-group-item list-group-item-action text-info bg-light">文档</a>
             <a href="https://github.com/dashingsoft/pyarmor-webui" target="_pyarmordoc" class="list-group-item list-group-item-action text-info bg-light">WebUI</a>
             <a href="https://github.com/dashingsoft/pyarmor/issues" target="_pyarmordoc" class="list-group-item list-group-item-action text-info bg-light">报告问题</a>