docs: update docusaurus to v3 (#5625)

* update dependencies

* update onboarding mdx

* fixes for mdx issues

* fixes for mdx compatibility

* resolve mdx errors

* fixes in reference

* fix check errors

* revert change in vale action

* fix node version in action

* fix summary in markdown

www/apps/docs/content/references/services/classes/DiscountRule.mdx

@@ -12,7 +12,7 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
 
 ### constructor
 
-**new DiscountRule**()
+`**new DiscountRule**()`
 
 A discount rule defines how a Discount is calculated when applied to a Cart.
 
@@ -21,7 +21,7 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
 <ParameterTypes parameters={[
   {
     "name": "allocation",
-    "type": "[`AllocationType`](../enums/AllocationType.mdx)",
+    "type": "[AllocationType](../enums/AllocationType.mdx)",
     "description": "The scope that the discount should apply to.",
     "optional": false,
     "defaultValue": "",
@@ -30,7 +30,7 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
   },
   {
     "name": "conditions",
-    "type": "[`DiscountCondition`](DiscountCondition.mdx)[]",
+    "type": "[DiscountCondition](DiscountCondition.mdx)[]",
     "description": "The details of the discount conditions associated with the rule. They can be used to limit when the discount can be used.",
     "optional": false,
     "defaultValue": "",
@@ -75,7 +75,7 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
   },
   {
     "name": "metadata",
-    "type": "Record<`string`, `unknown`\\>",
+    "type": "`Record<string, unknown>`",
     "description": "An optional key-value map with additional details",
     "optional": false,
     "defaultValue": "",
@@ -84,8 +84,8 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
   },
   {
     "name": "type",
-    "type": "[`DiscountRuleType`](../enums/DiscountRuleType.mdx)",
-    "description": "The type of the Discount, can be `fixed` for discounts that reduce the price by a fixed amount, `percentage` for percentage reductions or `free_shipping` for shipping vouchers.",
+    "type": "[DiscountRuleType](../enums/DiscountRuleType.mdx)",
+    "description": "The type of the Discount, can be `fixed` for discounts that reduce the price by a fixed amount, `percentage` for percentage reductions or `free\\_shipping` for shipping vouchers.",
     "optional": false,
     "defaultValue": "",
     "expandable": false,
@@ -115,7 +115,7 @@ A discount rule defines how a Discount is calculated when applied to a Cart.
 
 ### beforeInsert
 
-`Private` **beforeInsert**(): `void`
+`Private **beforeInsert**(): void`
 
 #### Returns