[ADD] purchase: How to import vendor pricelists

https://docs.google.com/document/d/1x48SpCFpzyUyU0BqRH-YkbVpThxvjwwmMx4Z_8Eb_Ro/edit#

purchase/purchases/master/import.rst

@@ -1,3 +1,124 @@
 ==================================
 How to import supplier pricelists?
-==================================
+==================================
+
+Introduction
+============
+
+Big companies use to import supplier pricelists day to day. Indeed,
+prices are always changing and you need to get price up to date to deal
+with a high number of products.
+
+To manage supplier prices on product form, read this document (:doc:`suppliers`). 
+Here we will show you how to import customer prices.
+
+Required configuration
+======================
+
+In purchase settings, you have 2 options:
+
+-  Manage vendor price on the product form
+
+-  Allow using and importing vendor pricelists
+
+Here we are selecting: **Allow using and importing vendor pricelists**
+
+.. image:: media/import05.png
+    :align: center
+
+Import vendor pricelists
+========================
+
+There are 2 scenarios: import the vendor pricelist for the first time,
+or update an existing vendor pricelist. In both scenarios, we assume
+your product list and vendor list is updated and you want to import the
+price list of vendors for a given product.
+
+.. note::
+    To understand big principle of import of data, we invite you to read related doc.
+
+To import a list from a document, the best pratice is to export first to
+get an example of data formating and a proper header to reimport.
+
+.. image:: media/import07.png
+    :align: center
+
+.. image:: media/import04.png
+    :align: center
+
+Import the list for the first time
+----------------------------------
+
+Prepare the document
+~~~~~~~~~~~~~~~~~~~~
+
+In :menuselection:`Purchase --> Purchase --> Supplier Pricelists`, 
+export a template of document to get import/export compatible and 
+get the right format to import in mass. Create manually a data and export it 
+(:menuselection:`select --> Action --> Export`)
+
+.. image:: media/import07.png
+    :align: center
+
+Here is the list of fields you can import:
+
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| **Header of the document to import (csv, xls)**     | **Meaning and how to get it**                                 | **Example**                            |
++=====================================================+===============================================================+========================================+
+| name_id                                             | Vendor ID -> export supplier list to get it                   | \_\_export\_\_.res\_partner\_12        |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| product_code                                        | Vendor product Code -> free text                              | 569874                                 |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| price                                               | Vendor Price -> free text                                     | 1500                                   |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| product_tmpl_id.id                                  | Product Template ID -> export you product list to get it      | \_\_export\_\_.product_template_13     |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| currency_id.id                                      | Currency -> to get it export the currency list                |                                        |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| date_end                                            | End date of the price validity                                | 2015-10-22                             |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| min_qty                                             | Minimal quantity to purchase from this vendor                 | 2                                      |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| product_id.id                                       | Product Variante name -> export your variant list to get it   | \_\_export\_\_.product\_13             |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+| date_start                                          | Start date of price validity                                  | 2015-12-31                             |
++-----------------------------------------------------+---------------------------------------------------------------+----------------------------------------+
+
+You obtain a document which can be imported, fill in your vendor pices
+
+.. image:: media/import02.png
+    :align: center
+
+Import this document in Odoo. Click on **Import** in the list view and
+upload your document. You can validate and check error. Once the system
+tells you everything is ok, you can import the list.
+
+.. image:: media/import01.png
+    :align: center
+
+.. image:: media/import06.png
+    :align: center
+
+After the import, the **Vendors** section in **Inventory** tab of the
+product form is filled in.
+
+Update the vendor pricelist
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When the pricelist of your suppliers change, it is necessary to update
+existing prices.
+
+Follow the procedure of the first scenario in order to export existing
+data from :menuselection:`Purchases --> Purchase --> Vendor Pricelist`. 
+Select everything, and export from the **Action** menu.
+
+Change price, end date, add a line, change a supplier, ... and then
+reimport in Odoo. Thanks to the ID, the list will be updated. Either the
+id is recognized and the line is updated or the ID is not known by Odoo
+and it will create a new pricelist line.
+
+After the import, the **Vendors** section in **Inventory** tab of the
+product form is updated.
+
+.. image:: media/import03.png
+    :align: center