Updated API from documentation release

Author: ct-sdks[bot]

api-specs/api/types/cart/updates/CartAddLineItemAction.raml

@@ -13,6 +13,8 @@ description: |
   If the Tax Rate is not set, a [MissingTaxRateForCountry](ctp:api:type:MissingTaxRateForCountryError) error is returned.
 
   If the Line Items do not have a Price according to the [Product](ctp:api:type:Product) `priceMode` value for a selected currency and/or country, Customer Group, or Channel, a [MatchingPriceNotFound](ctp:api:type:MatchingPriceNotFoundError) error is returned.
+
+  If the Line Items are added to a Cart bound to a Store with active Product Selections, the selected Product Variant must be [available in that Store](/../api/projects/stores#products-available-in-store), otherwise an [InvalidInput](ctp:api:type:InvalidInputError) error is returned.
 properties:
   key?:
     type: string