[ADD] inventory: How to unload your shipment to an input location? (2 steps)

https://docs.google.com/document/d/1oK8PKLfE8DbSvpWC2Rc2olNuzRlrKOtuAv_q28WsWqA/edit

inventory/incoming/two_steps.rst

@@ -1,3 +1,98 @@
 ===========================================================
 How to unload your shipment to an input location? (2 steps)
-===========================================================
+===========================================================
+
+Overview
+========
+
+Odoo uses routes to define exactly how you will handle the different
+receipt steps. The configuration is done at the level of the warehouse.
+By default, the reception is a one step process, but changing the
+configuration can allow to have 2 or even 3 steps.
+
+The 2 steps flow is the following : You receive the goods in an input
+area then transfer them from input area to your stock. As long as the
+goods are not transferred in your stock, they will not be available for
+further processing.
+
+This is the case that will be explained in this document.
+
+Configuration
+=============
+
+Use advanced routes
+-------------------
+
+To allow management of routes, go to the menu
+:menuselection:`Inventory --> Configuration --> Settings`
+
+.. image:: media/two_steps05.png
+   :align: center
+
+Ensure that the routes option **Advance routing of product using
+rules** is checked, then click on **Apply** to save changes.
+
+Make sure that **“Manage several locations per warehouse”** is also
+ticked.
+
+How to configure your warehouse ?
+---------------------------------
+
+Go to the the menu :menuselection:`Inventory --> Configuration --> Warehouse`
+and choose the warehouse where you want to change reception methods.
+
+By default, warehouses are configured with one step reception (option **Receive
+goods directly into stock**).
+
+To add the control step, tick **Unload in input location then go to
+stock (2 steps)**.
+
+.. image:: media/two_steps02.png
+   :align: center
+
+How to receipt a shipment in 2 steps ?
+======================================
+
+How to process the Receipt step ?
+---------------------------------
+
+-  In the purchase module, create a **Request for Quotation**, then click on
+   the **Confirm order** button. You can see that there is one
+   **Shipment** related to purchase order in the **stat button**
+   above the purchase order form view. This is the receipt step.
+
+.. image:: media/two_steps03.png
+   :align: center
+
+-  Go to **Inventory** and click on the **# TO RECEIVE** link on the
+   **Receipts** card.
+
+.. image:: media/two_steps01.png
+   :align: center
+
+Click on the receipt that you want to process, then click on **Validate** to
+complete the move from the **Vendor** to **WH/Input**.
+
+This has completed the Receipt Step and the move refered with **WH/IN**. 
+The product has been moved from the **Vendor** to the **WH/Input** location, 
+which makes the product available for the next step.
+
+How to to transfer the receipt to your stock ? 
+-----------------------------------------------
+
+Go back to the **Inventory** dashboard. The waiting transfer is now
+ready. Click on the **# TRANSFERS** in the **Internal Transfers** to process
+the quality control.
+
+.. image:: media/two_steps04.png
+   :align: center
+
+Click on the picking you want to process. Click on **Validate** to
+complete the move from **WH/Input** to **WH/Stock**.
+
+This has completed the internal transfer step and the move refered with **WH/INT**. 
+The receipt has been moved to your stock.
+
+.. seealso::
+    * :doc:`../delivery/inventory_flow`
+    * :doc:`three_steps`