Fix documentation

Author: vdespa

simple-grocery-store-api.md

@@ -260,10 +260,10 @@ Deletes an item in the cart.
 
 **Parameters**
 
-| Name        | Type   | In   | Required | Description               |
-| ----------- | ------ | ---- | -------- | ------------------------- |
-| `cartId`    | string | path | Yes      | Specifies the cart id.    |
-| `productId` | string | path | Yes      | Specifies the product id. |
+| Name        | Type   | In   | Required | Description             |
+| ----------- | ------ | ---- | -------- | ----------------------- |
+| `cartId`    | string | path | Yes      | Specifies the cart id.  |
+| `itemId`    | string | path | Yes      | Specifies the item id.  |
 
 **Status codes**