docs: changed label and Headers of introduction page (#2327)

* Changed label and Headers of introduction page

* Edited Storefront Header

docs/content/introduction.md

@@ -1,20 +1,20 @@
 ---
-title: Introduction
+title: Architecture Overview
 ---
 
-## Architecture overview
+# Architecture Overview
 
 Medusa is composed of three components: The headless backend, the admin dashboard, and the storefront.
 
 ![Medusa's Architecture](https://i.imgur.com/ZHvM2bu.png)
 
-### Headless Backend
+## Headless Backend
 
 This is the main component that holds all the logic and data of the store. Your admin dashboard and storefront interact with the backend to retrieve, create, and modify data through REST APIs.
 
 Your Medusa server will include all functionalities related to your store’s checkout workflow. That includes cart management, shipping and payment providers, user management, and more. It also allows you to configure your store including your store’s region, tax rules, discounts, gift cards, and more.
 
-### Admin Dashboard
+## Admin Dashboard
 
 The admin dashboard is accessible by store operators. Store operators can use the admin dashboard to view, create, and modify data such as orders and products.
 
@@ -22,6 +22,6 @@ Medusa provides a beautiful [admin dashboard](https://demo.medusajs.com) that yo
 
 You can also create your own admin dashboard by utilizing the [Admin REST APIs](https://docs.medusajs.com/api/admin).
 
-### Storefront
+## Storefront
 
 Your customers use the Storefront to view products and make orders. Medusa provides two storefronts, one built with [Next.js](https://docs.medusajs.com/starters/nextjs-medusa-starter) and one with [Gatsby](https://docs.medusajs.com/starters/gatsby-medusa-starter). You are also free to create your own storefront using the [Storefront REST APIs](https://docs.medusajs.com/api/store/).

www/docs/sidebars.js

@@ -23,7 +23,7 @@ module.exports = {
         {
           type: "doc",
           id: "introduction",
-          label: "Introduction",
+          label: "Architecture Overview",
         },
         {
           type: "doc",