chore(oas): [16/n] improve oas schemas (#9272)

- Improve OAS schemas [16/n]
- fixes and improvements to docs-generator tool

www/utils/generated/oas-output/schemas/BaseExchangeItem.ts

@@ -1,7 +1,7 @@
 /**
  * @schema BaseExchangeItem
  * type: object
- * description: The additional item's additional items.
+ * description: The item's details.
  * x-schemaName: BaseExchangeItem
  * required:
  *   - id
@@ -15,36 +15,36 @@
  *   id:
  *     type: string
  *     title: id
- *     description: The additional item's ID.
+ *     description: The item's ID.
  *   exchange_id:
  *     type: string
  *     title: exchange_id
- *     description: The additional item's exchange id.
+ *     description: The ID of the exchange this item belongs to.
  *   order_id:
  *     type: string
  *     title: order_id
- *     description: The additional item's order id.
+ *     description: The ID of the order this item belongs to.
  *   item_id:
  *     type: string
  *     title: item_id
- *     description: The additional item's item id.
+ *     description: The ID of the item in the order.
  *   quantity:
  *     type: number
  *     title: quantity
- *     description: The additional item's quantity.
+ *     description: The item's quantity.
  *   metadata:
  *     type: object
- *     description: The additional item's metadata.
+ *     description: The item's metadata, can hold custom key-value pairs.
  *   created_at:
  *     type: string
  *     format: date-time
  *     title: created_at
- *     description: The additional item's created at.
+ *     description: The date the item was created.
  *   updated_at:
  *     type: string
  *     format: date-time
  *     title: updated_at
- *     description: The additional item's updated at.
+ *     description: The date the item was updated.
  * 
 */