[ADD] inventory: Add a 'Immediate & Planned Transfers' page

Original document: https://docs.google.com/document/d/1c1rXpWRAdlHobWTH6X7RCzl0gDQ8KlROJw5vFHyrFmE/edit

inventory/management/misc.rst

@@ -9,3 +9,4 @@ Miscellaneous Operations
    misc/scrap
    misc/owned_stock
    misc/schedulers
+   misc/immediate_planned_transfers

inventory/management/misc/immediate_planned_transfers.rst

@@ -0,0 +1,40 @@
+Immediate & Planned Transfers
+=============================
+
+In Odoo, you can create two types of transfers: immediate or planned
+transfers.
+
+Immediate Transfers
+-------------------
+
+When you create a transfer manually, it is by default an immediate
+transfer.
+
+In the case of an immediate transfer, you directly encode the products
+and quantities you are processing, there is no reservation that applies.
+This is why the column "Initial Demand" is not editable. You only fill
+in the column "Done" for the quantities.
+
+This is for example used when you are transferring goods from a location
+A to a location B and that this is not planned (you are processing the
+transfer right now).
+
+Planned Transfers
+-----------------
+
+When a transfer is generated automatically (from a sales order or
+purchase order for example), it is a planned transfer. This means that
+there is an initial demand and that reservation applies on this initial
+demand.
+
+If you want to create a planned transfer manually, you can do it from
+the inventory dashboard.
+
+.. image:: media/immediate_planned_transfers01.png
+    :align: center
+
+In that case, you will have to enter the initial demand first (how many
+units are you supposed to proceed), then to mark your transfer as to do.
+Once this is done, you will be able to reserve the products and to
+process the transfer.
+