fix layout issue with ui.refreshable

nicegui/functions/refreshable.js

@@ -0,0 +1,3 @@
+export default {
+  template: `<slot></slot>`,
+};

nicegui/functions/refreshable.py

@@ -2,8 +2,11 @@ from typing import Callable, List
 
 from typing_extensions import Self
 
+from ..dependencies import register_component
 from ..element import Element
 
+register_component('refreshable', __file__, 'refreshable.js')
+
 
 class refreshable:
 
@@ -22,7 +25,7 @@ class refreshable:
         return self
 
     def __call__(self) -> None:
-        with Element('div') as container:
+        with Element('refreshable') as container:
             self.func() if self.instance is None else self.func(self.instance)
         self.containers.append(container)