doc: 补充 IsVirtualize 参数文档

Author: ArgoZhang

src/BootstrapBlazor.Server/Components/Samples/TreeViews.razor.cs

@@ -354,6 +354,14 @@ private static AttributeItem[] GetAttributes() =>
             DefaultValue = "false"
         },
         new()
+        {
+            Name = nameof(TreeView<string>.IsVirtualize),
+            Description = "Virtualize",
+            Type = "bool",
+            ValueList = "true|false",
+            DefaultValue = "false"
+        },
+        new()
         {
             Name = nameof(TreeView<string>.CanExpandWhenDisabled),
             Description = "Whether to expand when the control node is disabled",