chore(readme): improve deploy button

Author: benjamincanac

README.md

@@ -29,7 +29,7 @@ Once the directory is created, you can install the dependencies and start the de
 
 ## Deploy your own
 
-[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https%3A%2F%2Fgithub.com%2Fnuxt-ui-templates%2Fdashboard-vue)
+[![Deploy with Vercel](https://vercel.com/button)](https://vercel.com/new/clone?repository-url=https%3A%2F%2Fgithub.com%2Fnuxt-ui-templates%2Fdashboard-vue&demo-image=https%3A%2F%2Fui4.nuxt.com%2Fassets%2Ftemplates%2Fvue%2Fdashboard-dark.png&demo-url=https%3A%2F%2Fdashboard-vue-template.nuxt.dev%2F&demo-title=Vue%20Dashboard%20Template&demo-description=A%20dashboard%20template%20with%20multi-column%20layout%20for%20building%20sophisticated%20admin%20interfaces.)
 
 ## Setup