[ADD] accounting: Switzerland Accounting Localization

Based on https://docs.google.com/document/d/1wQ7IFkWPxxZ9P9QPyJWQmaw2eOYkhBF2r8lpmEs88sU/edit#

accounting.rst

@@ -12,4 +12,5 @@ Accounting
    accounting/payables
    accounting/bank
    accounting/others
+   accounting/localizations
 

accounting/localizations.rst

@@ -0,0 +1,8 @@
+=============
+Localizations
+=============
+
+.. toctree::
+   :titlesonly:
+
+   localizations/switzerland

accounting/localizations/switzerland.rst

@@ -0,0 +1,46 @@
+===================================
+Switzerland Accounting Localization
+===================================
+
+ISR (In-payment Slip with Reference number)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ISRs are payment slips used in Switzerland. You can print them
+directly from Odoo. On the customer invoices, there is a new button
+called *Print ISR*.
+
+.. image:: media/switzerland00.png
+    :align: center
+
+.. tip:: 
+    The button *Print ISR* only appears there is well a bank account
+    defined on the invoice. You can use CH6309000000250097798 as bank
+    account number and 010391391 as CHF ISR reference.
+
+.. image:: media/switzerland01.png
+    :align: center
+
+Then you open a pdf with the ISR.
+
+.. image:: media/switzerland02.png
+    :align: center
+
+There exists two layouts for ISR: one with, and one without the bank
+coordinates. To choose which one to use, there is an option to print the
+bank information on the ISR. To activate it, go in
+:menuselection:`Accounting --> Configuration --> Settings --> Accounting Reports`
+and tick this box :
+
+.. image:: media/switzerland03.png
+    :align: center
+
+Currency Rate Live Update
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can update automatically your currencies rates based on the Federal
+Tax Administration from Switzerland. For this, go in
+:menuselection:`Accounting --> Settings`, activate the multi-currencies setting and choose the service
+you want.
+
+.. image:: media/switzerland04.png
+    :align: center