GraphQL: Add staging attribute (#8280)

Author: keharper

src/guides/v2.4/graphql/interfaces/category-interface.md

@@ -27,6 +27,7 @@ Attribute | Type | Description
 `position` | Int | The position of the category relative to other categories at the same level in tree
 `product_count` | Int | The number of products in the category that are marked as visible. By default, in complex products, parent products are visible, but their child products are not
 `products(<attributes>)` | CategoryProducts | The list of products assigned to the category
+`staged` | Boolean! | Indicates whether the category is staged for a future campaign
 `updated_at` | String | Timestamp indicating when the category was updated
 `url_key` | String | The URL key assigned to the category
 `url_path` | String | The URL path assigned to the category

src/guides/v2.4/graphql/interfaces/product-interface.md

@@ -61,6 +61,7 @@ Attribute | Data type | Description
 `special_from_date` | String | The beginning date that a product has a special price
 `special_price` | Float |  The discounted price of the product
 `special_to_date` | String | The end date that a product has a special price
+`staged` | Boolean! | Indicates whether the product is staged for a future campaign
 `stock_status` | ProductStockStatus | The status of the stock. `ProductStockStatus` is an enumeration that can have the value of `IN_STOCK` or `OUT_OF_STOCK`. This attribute is defined in the `InventoryGraphQl` module.
 `swatch_image` | String | The file name of a swatch image. This attribute is defined in the `SwatchesGraphQl` module.
 `tax_class_id` | Int | An ID assigned to a tax class. This attribute is defined in the `TaxGraphQl` module.