[ADD] purchase: How to control received products?

https://docs.google.com/document/d/1Z_4YcItrIrK05aLYc7ONyBvGKFsffpe1O9prccM9c4g/edit#heading=h.85s8qikbwxiy

purchase/purchases/rfq/reception.rst

@@ -1,3 +1,121 @@
 =======================================================
 How to control product received? (entirely & partially)
-=======================================================
+=======================================================
+
+The **Purchase** app allows you to manage your purchase orders, to control
+products to receive and to control supplier bills.
+
+If you want to get product forecasts and receptions under control, the
+first thing to do is to deploy the Odoo purchase process. Knowing what
+have been purchased is the basis of forecasting and controlling
+receptions.
+
+Configuration
+=============
+
+Install the Purchase and Inventory applications
+-----------------------------------------------
+
+Start by installing the Purchase application from the **Apps** module.
+This will automatically trigger the installation of the **Inventory** app
+(among others), which is required with **Purchase**.
+
+.. image:: media/reception02.png
+    :align: center
+
+Create products
+---------------
+
+Then, you need to create the products you want to purchase. Go to the
+**Purchase** app, then :menuselection:`Purchase --> Products`, 
+and click on **Create**.
+
+.. image:: media/reception05.png
+    :align: center
+
+When creating the product, the **Product Type** field is important:
+
+-   **Stockable & Consumable**: products need to be received in the
+    inventory.
+
+-   **Services & Digital Products** (only when the **eCommerce** app is
+    installed): there is no control about what you receive or not.
+
+.. tip:: 
+    It's always good to create a **Miscellaneous** product for all 
+    the products you purchased rarely and for which you don’t want 
+    to manage the stocks or have purchase/sale statistics. 
+    If you create such a product, we recommend to set his product 
+    type field as **Service**.
+
+Control products receptions
+===========================
+
+Purchase products
+-----------------
+
+From the purchase application, create a purchase order with a few
+products. If the vendor sent you a sale order or a quotation, put its
+reference in the **Vendor Reference** field. This will allow you to easily
+do the matching with the delivery order later on (as the delivery order
+will probably include the **Vendor Reference** of his sale order).
+
+.. image:: media/reception03.png
+    :align: center
+
+.. note:: 
+    See the documentation page :doc:`../../overview/process/from_po_to_invoice` 
+    for a full overview of the purchase process.
+
+Receive Products
+----------------
+
+If you purchased physical goods (stockable or consumable products), you
+can receive the products from the **Inventory** application. From the
+**Inventory** dashboard, you should see a button **X To Receive**, on the
+receipt box of the related warehouse.
+
+.. image:: media/reception01.png
+    :align: center
+
+Click on this button and you access a list of all awaiting orders for
+this warehouse.
+
+.. image:: media/reception07.png
+    :align: center
+
+If you have a lot of awaiting orders, you can use the filter bar to
+search on the **Vendor** (also called **Partner** in Odoo), the product or the
+source document, which is the reference of your purchase order. You can
+open the document that matches with the received delivery order and
+process all the lines within it.
+
+.. image:: media/reception04.png
+    :align: center
+
+You may validate the whole document at once by clicking on the
+**Validate** button or you can control all products, one by one, by
+manually change the **Done** quantity (what has actually been received).
+When a line is green, it means the quantity received matches to what
+have been expected.
+
+.. note::
+    If you work with lots or serial numbers, you can not set 
+    the processed quantity, but you have to provide all the 
+    lots or serial numbers to record the quantity received.
+
+When you validate the reception, if you have received less products than
+the initial demand, Odoo will ask youthe permission to create a
+backorder.
+
+.. image:: media/reception06.png
+    :align: center
+
+If you plan to receive the remaining product in the future, select
+**Create Backorder**. Odoo will create a new documents for the awaiting
+products. If you choose **No Backorder**, the order is considered as
+fulfilled.
+
+.. seealso::
+    * :doc:`bills`
+    * :doc:`cancel`