docs: clarify ISO format for province codes (#12282)

* docs: clarify ISO format for province codes

* regenerate

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

@@ -53,7 +53,11 @@
  *   province:
  *     type: string
  *     title: province
- *     description: The address's province.
+ *     description: The address's lower-case ISO 3166-2 province code.
+ *     example: "US-CA"
+ *     externalDocs:
+ *       url: https://en.wikipedia.org/wiki/ISO_3166-2
+ *       description: Learn more about ISO 3166-2
  *   postal_code:
  *     type: string
  *     title: postal_code