allow changing the number of root nodes

packages/core/src/fragment.rs

@@ -32,7 +32,7 @@ pub fn Fragment<'a>(cx: Scope<'a, FragmentProps<'a>>) -> Element {
         key: children.key,
         parent: children.parent,
         template: children.template.clone(),
-        root_ids: children.root_ids,
+        root_ids: children.root_ids.clone(),
         dynamic_nodes: children.dynamic_nodes,
         dynamic_attrs: children.dynamic_attrs,
     })