[ADD] inventory: How to process delivery orders in three steps (pick + pack + ship)?

https://docs.google.com/document/d/1zQF_WUwmOx_W1p7MeIsBdaVTKfUryfnM0NaXgFXoAAA/edit#heading=h.teahchhagxca

inventory/delivery/three_steps.rst

@@ -1,3 +1,163 @@
 ===================================================================
 How to process delivery orders in three steps (pick + pack + ship)?
-===================================================================
+===================================================================
+
+Overview
+========
+
+When an order goes to the shipping department for final delivery, Odoo
+is set up by default on a **one-step** operation: once all goods are
+available, they can be shipped in bulk in a single delivery order.
+However, that process may not reflect the reality and your company may
+require more steps before shipping.
+
+With the **three steps** process (**Pick + Pack + Ship**), the items are
+transferred to a packing area, where they will be assembled by area of
+destination, and then set to outbound trucks for final delivery to the
+customers.
+
+A few configuration steps are necessary in order to accomplish **Pick +
+Pack + Ship** in Odoo. These steps create some additional locations, which
+by default are called **Output** and **Packing Zone**. So, if your warehouse’s
+code is ``WH``, this configuration will create a location called ``WH/Output``
+and another one called ``WH/Packing Zone``.
+
+Goods will move from **WH/Stock** to **WH/Packing Zone** in the first step.
+Then move from **WH/Packing Zone** to **WH/Output**. Then finally it will be
+delivered from **WH/Output** to its **final destination**.
+
+.. note::
+    Check out :doc:`inventory_flow` to determine if this inventory flow is 
+    the correct method for your needs.
+
+Configuration
+=============
+
+Install the Inventory module
+----------------------------
+
+From the **App** menu, search and install the **Inventory** module.
+
+.. image:: media/three_steps07.png
+   :align: center
+
+You will also need to install the **Sales** module to be able to issue sales
+orders.
+
+Allow managing routes
+---------------------
+
+Odoo configures movement of delivery orders via **routes**. Routes
+provide a mechanism to link different actions together. In this case, we
+will link the picking step to the shipping step.
+
+To allow management of routes, go to :menuselection:`Configuration --> Settings`
+
+Under :menuselection:`Location & Warehouse --> Routes`, activate the radio button
+**Advanced routing of products using rules**. Make sure that the option
+**Manage several locations per warehouse** is activated as well.
+
+.. image:: media/three_steps05.png
+   :align: center
+
+Configure the warehouse for Pick + Pack + Ship
+-----------------------------------------------
+
+Go to :menuselection:`Configuration --> Warehouses` and edit the warehouse that will be
+used.
+
+For outgoing shippings, set the option to **Make packages into a
+dedicated location, bring them to the output location for shipping (Pick
++ Pack + Ship).**
+
+.. image:: media/three_steps01.png
+   :align: center
+
+Create a Sale Order
+===================
+
+From the **Sale** module, create a sales order with some products to deliver.
+
+Notice that we now see ``3`` transfers associated with this sales order
+in the **stat button** above the sales order.
+
+.. image:: media/three_steps06.png
+   :align: center
+
+If you click the button, you should now see three different pickings:
+
+1.  The first with a reference **PICK** to designate the picking process,
+
+2.  The second one with the reference **PACK** that is the packing process,
+
+3.  The last with a reference **OUT** to designate the shipping process.
+
+.. image:: media/three_steps04.png
+   :align: center
+
+Process a Delivery
+==================
+
+How to Process the Picking Step?
+--------------------------------
+
+Ensure that you have enough product in stock and Go to **Inventory** 
+and click on the **Waiting** link under the **Pick** kanban card.
+
+.. image:: media/three_steps08.png
+   :align: center
+
+Click on the picking that you want to process.
+
+Click on **Reserve** to reserve the products if they are available.
+
+Click on **Validate** to complete the move from **WH/Stock** to **WH/Packing Zone**.
+
+This has completed the picking Step and the **WH/PICK** should now show
+**Done** in the status column at the top of the page. The product has
+been moved from **WH/Stock** to **WH/Packing Zone** location, which makes the
+product available for the next step (Packing).
+
+How to Process the Packing Step?
+--------------------------------
+
+Go to **Inventory** and click on the **# TRANSFERS** link under the
+**Pack** kanban card.
+
+.. image:: media/three_steps03.png
+   :align: center
+
+Click on the picking that you want to process.
+
+Click on **Validate** to complete the move from **WH/Packing Zone** to
+**WH/Output**.
+
+This has completed the packing step and the **WH/PACK** should now show
+**Done** in the status column at the top of the page. The product has
+been moved from **WH/Packing Zone** to **WH/Output location**, which makes the
+product available for the next step (Shipping).
+
+How to Process the Shipping Step?
+---------------------------------
+
+Go to **Inventory** and click on the **# TO DO** link under the
+**Delivery Orders** kanban card.
+
+.. image:: media/three_steps02.png
+   :align: center
+
+Click on the picking that you want to process.
+
+Click on **Validate** to complete the move from **WH/Output** to the
+**customer** (Click **Apply** to assign the quantities based on the
+quantities listed in the **To Do** column).
+
+This has completed the shipping step and the **WH/OUT** should now show
+**Done** in the status column at the top of the page. The product has
+been shipped to the customer.
+
+.. todo::
+    Link to these sections when available
+    -  Process Overview: From sales orders to delivery orders
+
+    -  Process Overview: From purchase orders to receptions