docs: make code blocks collapsible (#7606)

* added collapsible code feature

* fixed side shadow

* fix build errors

* change design

* make code blocks collapsible

www/apps/resources/app/commerce-modules/cart/promotions/page.mdx

@@ -41,7 +41,7 @@ Learn more about actions in the [Promotion Module’s documentation](../../promo
 
 </Note>
 
-```ts
+```ts collapsibleLines="1-8" expandButtonLabel="Show Imports"
 import {
   ComputeActionAdjustmentLine,
   ComputeActionItemLine,
@@ -101,7 +101,7 @@ The `computeActions` method accepts the existing adjustments of line items and s
 
 Then, use the returned `addItemAdjustment` and `addShippingMethodAdjustment` actions to set the cart’s line item and the shipping method’s adjustments.
 
-```ts
+```ts collapsibleLines="1-9" expandButtonLabel="Show Imports"
 import {
   AddItemAdjustmentAction,
   AddShippingMethodAdjustment,