doc: add stackblitz demo to introduction

docs/content/nuxtSeo/2.guides/0.using-the-modules.md

@@ -3,6 +3,16 @@ title: Quick Module Setup Guide
 description: A quick guide on which features are available on activating Nuxt SEO.
 ---
 
+## Introduction
+
+Nuxt SEO is a collection of 6 modules, while most will just work-out-of-the-box, there may be some configuration needed
+depending on your site's requirements.
+
+This guide will give you a quick overview of each module and what you need to do to get started.
+
+Check out the [Stackblitz Demo](https://stackblitz.com/edit/nuxt-starter-gfrej6?file=nuxt.config.ts) if you want to 
+see a working example.
+
 ## Sitemap
 
 :ModuleCard{slug="sitemap" class="w-1/2"}