docs: update badges

docs/content/2.elements/3.avatar.md

@@ -4,6 +4,8 @@ links:
   - label: GitHub
     icon: i-simple-icons-github
     to: https://github.com/nuxt/ui/blob/dev/src/runtime/components/elements/Avatar.vue
+navigation:
+  badge: 'New'
 ---
 
 ## Usage

docs/content/2.elements/5.button.md

@@ -4,6 +4,8 @@ links:
   - label: GitHub
     icon: i-simple-icons-github
     to: https://github.com/nuxt/ui/blob/dev/src/runtime/components/elements/Button.vue
+navigation:
+  badge: 'New'
 ---
 
 ## Usage
@@ -276,7 +278,7 @@ excludedProps:
 To stack buttons as a group, use the `ButtonGroup` component.
 
 - To size all the buttons equally, pass the `size` prop
-- To change the orientation of the buttons, set the `orientation` prop to `vertical`
+- To change the orientation of the buttons, set the `orientation` prop to `vertical` :u-badge{label="New" class="!rounded-full" variant="subtle"}
 - To adjust the rounded or the shadow around buttons, customize with `ui.buttonGroup.rounded` or `ui.buttonGroup.shadow`
 
 ::component-card{slug="ButtonGroup"}