adds a empty state for no components added in the repeater

packages/client/src/components/Component.svelte

@@ -29,7 +29,7 @@
     $builderStore.previewType === "layout" || screenslotContext
 
   // Update component context
-  $: componentStore.set({ id, styles: { ...styles, id, allowSelection } })
+  $: componentStore.set({ id, children: children.length, styles: { ...styles, id, allowSelection } })
 
   // Gets the component constructor for the specified component
   const getComponentConstructor = component => {

packages/standard-components/src/List.svelte

@@ -28,7 +28,11 @@
   {#if rows.length > 0}
     {#each rows as row}
       <DataProvider {row}>
-        <slot />
+        {#if $component.children === 0}
+         <p>Add some components to.</p>
+        {:else}
+          <slot />
+        {/if}
       </DataProvider>
     {/each}
   {:else}