docs: fix details about maximum quantity for promotions (#13642)

www/apps/book/public/llms-full.txt

@@ -35864,6 +35864,46 @@ The application method has a collection of `PromotionRule` items to define the
 
 In this example, the cart must have two product variants with the SKU `SHIRT` for the promotion to be applied.
 
+***
+
+## Maxiumum Quantity Restriction
+
+When the `allocation` property in the `ApplicationMethod` is set to `each`, you can restrict the maximum quantity of each applicable item that the promotion is applied to in the cart.
+
+For example, if the maximum quantity is set to `1` and the customer has a line item with quantity two in the cart, the promotion is only applied to one of them.
+
+```json title="Example Cart"
+{
+  "cart": {
+    "items": [
+      {
+        "id": "item_1",
+        "quantity": 2 // The promotion is applied to 1 of this item
+      }
+    ]
+  }
+}
+```
+
+This condition is applied on the quantity of every applicable item in the cart. For example, if set to `1` and the customer has two applicable items in the cart, the promotion is applied to one of each of them.
+
+```json title="Example Cart"
+{
+  "cart": {
+    "items": [
+      {
+        "id": "item_1",
+        "quantity": 2 // The promotion is applied to 1 of this item
+      },
+      {
+        "id": "item_2",
+        "quantity": 3 // The promotion is applied to 1 of this item
+      }
+    ]
+  }
+}
+```
+
 
 # Campaign