docs: Adds guides for plugins and storefront starters (#840)

docs/content/starters/nextjs-medusa-starter.md

@@ -0,0 +1,39 @@
+# Quickstart: Next.js
+
+**Create a new Next.js project using the Medusa starter template**
+```bash
+npx create-next-app -e https://github.com/medusajs/nextjs-starter-medusa my-medusa-storefront
+```
+
+**Set up environment variables**
+Navigate into your projects directory and get your environment variables ready:
+
+```shell
+mv .env.template .env.local
+```
+
+**Install dependencies**
+Use your favourite package manager to install dependencies:
+```shell
+yarn
+# or
+npm install
+```
+
+**Start developing.**
+Start up the local server:
+```shell
+yarn dev
+```
+
+Your site is now running at http://localhost:8000!
+
+Edit `src/pages/index.js` to see your site update in real-time!
+
+**Learn more about Medusa**
+- [Website](https://www.medusa-commerce.com/)
+- [GitHub](https://github.com/medusajs)
+- [Documentation](https://docs.medusa-commerce.com/)
+
+**Learn more about Next.js**
+- [Documentation](https://nextjs.org/docs)