[ADD] POS: page to setup and use product combos

Task-3604850

closes odoo/documentation#7341

Signed-off-by: Loredana Perazzo (lrpz) <lrpz@odoo.com>

content/applications/sales/point_of_sale.rst

@@ -173,6 +173,7 @@ the **POS dashboard**.
 
    point_of_sale/employee_login
    point_of_sale/receipts_invoices
+   point_of_sale/combos
    point_of_sale/configuration
    point_of_sale/shop
    point_of_sale/restaurant

content/applications/sales/point_of_sale/combos.rst

@@ -0,0 +1,60 @@
+==============
+Product combos
+==============
+
+The **Product Combos** feature allows users to define and manage combination options for a single
+product.
+
+In the context of a restaurant, the feature enables users to create multiple-choice menus. For
+example, a user can define a main dish and specify various options for sides, drinks, or desserts
+that customers can combine with the main dish.
+
+In retail, this feature allows you to create a product set with multiple products to choose from and
+combine.
+
+Configuration
+=============
+
+First, you need to create combination choices. To do so:
+
+#. Go to :menuselection:`Point of Sale --> Products --> Product Combos` and click :guilabel:`New`.
+#. Name your combo and add the products you want customers to choose from by clicking :guilabel:`Add
+   a line`. You can also include an extra price for each option in the :guilabel:`Extra Price`
+   column.
+
+.. note::
+   As a reference, the selected product's original price is displayed in the :guilabel:`Original
+   Price` column.
+
+.. image:: combos/combo-form.png
+   :scale: 75%
+
+Second, you need to create a specific product to gather combo choices. To do this:
+
+#. Go to :menuselection:`Point of Sale --> Products --> Products` and click :guilabel:`New`.
+#. Set the :guilabel:`Product Type` to :guilabel:`Combo` and fill in the  :guilabel:`General
+   Information` tab.
+
+   .. note::
+      The sales price of the combo product is fixed and does not vary based on the individual prices
+      of included items or the quantity of items in the combo. The combo product price is only
+      affected by the extra price optionally defined at the combo choice creation or if a variant of
+      one of the items has a specified extra price.
+#. Go to the :guilabel:`Combo Choices` tab, click :guilabel:`Add a line`, and select the
+   combinations to add. You can also create a new combination at this step by clicking
+   :guilabel:`New` on the popup window.
+
+.. image:: combos/combo-product-form.png
+   :scale: 75%
+
+Once you have created and added the combo choices into a product, you can sell combos in your retail
+store or restaurant.
+
+Practical application
+=====================
+
+:ref:`Open a POS session <pos/session-start>` and select the combo product. Choose the options and
+click :guilabel:`Add to order`. As a reminder, the extra price appears under the related choices.
+
+.. image:: combos/combo-select.png
+   :scale: 75%