PROGX-1048: max_items_count documentation (#1122)

Author: jmleroux

content/swagger/akeneo-web-api.json

@@ -227,9 +227,14 @@ properties:
     x-warning: Only for `pim_catalog_number` or `pim_catalog_metric` attribute types
   enable_option_creation_during_import:
     type: boolean
-    description: Whether new attribute options can be created automatically during product or product model import (CSV, XLSX). This feature will be available soon.
+    description: Whether new attribute options can be created automatically during product or product model import (CSV, XLSX), when the attribute type is `pim_catalog_simpleselect` or `pim_catalog_multiselect`.
     x-warning: Only for `pim_catalog_simpleselect` or `pim_catalog_multiselect` attribute types
     x-from-version: "SaaS"
+  max_items_count:
+    type: number
+    description: Maximum number of items allowed in an asset collection when the attribute type is `pim_catalog_asset_collection`.
+    x-warning: Only for `pim_catalog_asset_collection` attribute types
+    x-from-version: "SaaS"
 example:
   {
     "code": "release_date",
@@ -262,5 +267,6 @@ example:
     "labels": { "en_US": "Sale date", "fr_FR": "Date des soldes" },
     "is_mandatory": false,
     "decimal_places_strategy": null,
-    "decimal_places": null
+    "decimal_places": null,
+    "max_items_count": null
   }