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/advanced/ecommerce/handle-order-claim-event.md

@@ -1,3 +1,8 @@
+---
+description: 'Learn how to handle the order claim event in the Medusa server. When the event is triggered, you can send an email to the customer to inform them about it.'
+addHowToData: true
+---
+
 # How to Handle Order Claim Event
 
 In this document, you’ll learn how to handle the order claim event and send a confirmation email when the event is triggered.

docs/content/advanced/ecommerce/send-gift-card-to-customer.md

@@ -1,4 +1,9 @@
-# Send Gift Card Code to Customer
+---
+description: 'Learn how to send a gift card code to the customer. Once the customer purchases a gift card, an email can be sent with the code so that they can redeem the gift card.'
+addHowToData: true
+---
+
+# How to Send Gift Card Code to Customer
 
 In this document, you’ll learn how to send a customer the gift card code they purchased.