docs: update link to SB playground

Author: atinux

.demo/content/1.index.md

@@ -22,7 +22,7 @@ A lightweight Nuxt theme to build a Markdown driven website, based on [Nuxt Cont
 
 ## Setup
 
-::button-link{icon="simple-icons:stackblitz" href="https://stackblitz.com/edit/nuxt-content-wind?file=content%2F1.index.md" external}
+::button-link{icon="simple-icons:stackblitz" href="https://stackblitz.com/github/Atinux/content-wind/tree/main/.demo?file=content%2F1.index.md" external}
 Play online on Stackblitz
 ::