docs: improved SEO of documentation (#3117)

* docs: added description to documentation pages

* docs: added more descriptions

* docs: finished improving meta description

* docs: added searchbox structured data

* docs: added breadcrumbs structured data

* docs: added how to structured data

* docs: improved 404 page

* docs: added how-to frontmatter option

docs/content/user-guide/regions/index.md

@@ -1,5 +1,6 @@
 ---
 sidebar_position: 1
+description: 'Medusa admin allows merchants to manage regions. Regions represent different countries within an ecommerce store.'
 ---
 
 # Regions Overview

docs/content/user-guide/regions/manage.mdx

@@ -1,5 +1,7 @@
 ---
 sidebar_position: 2
+description: 'This user guide explains how to manage regions on the Medusa admin. Learn how to create and edit regions.'
+addHowToData: true
 ---
 
 import UiIcon from '@site/src/components/UiIcon';

docs/content/user-guide/regions/providers.mdx

@@ -1,11 +1,13 @@
 ---
 sidebar_position: 3
 sidebar_label: Manage Providers
+description: 'This user guide explains how to manage payment and fulfillment providers in a region on the Medusa admin.'
+addHowToData: true
 ---
 
 import UiIcon from '@site/src/components/UiIcon';
 
-# Manage Payment and Fulfillment Providers
+# Manage Payment and Fulfillment Providers in a Region
 
 In this document, you’ll learn how to manage a region’s payment and fulfillment providers in your Medusa Admin.
 

docs/content/user-guide/regions/shipping-options.mdx

@@ -1,10 +1,13 @@
 ---
 sidebar_position: 4
+sidebar_label: Manage Shipping Options
+description: 'This user guide explains how to manage shipping options in a region on the Medusa admin.'
+addHowToData: true
 ---
 
 import UiIcon from '@site/src/components/UiIcon';
 
-# Manage Shipping Options
+# Manage Shipping Options in a Region
 
 In this document, you’ll learn how to manage a region’s shipping options in your Medusa Admin.