docs: Update Vue label to 'vue 3' in playgrounds index (#5501)

Author: mfranzke

showcases/patternhub/pages/foundations/playgrounds/index.mdx

@@ -22,7 +22,7 @@ We would also appreciate it if you could provide a working example when opening
     <a href="https://codesandbox.io/s/github/db-ux-design-system/examples/tree/main/vue-example">
     	<DBCard behavior="interactive">
     		![](/assets/images/vue-showcase.svg)
-    		<strong>Vue</strong>
+    		<strong>vue 3</strong>
     		Vue app including `@db-ux/v-core-components`
     	</DBCard>
     </a>