[ADD] sales : invoice & deliver + get signature to validate

origin invoice: https://docs.google.com/document/d/1ZwOpoQ9bvuPM3PHySUzEsT3oKpGaabzdnVc0sdiuYVw/edit
origin get signature: https://docs.google.com/document/d/1OkC9MVvuDvzz2b9gZjfzMPzep7qdbOyZZxE0ZZj2K7E/edit

sales/send_quotations/getsignaturetovalidate.rst

@@ -0,0 +1,32 @@
+===================================
+Get a signature to confirm an order
+====================================
+
+You can use online signature to get orders automatically confirmed. Both
+you and your customer will save time by using this feature compared to a
+traditional process.
+
+Activate online signature
+==========================
+
+Go to :menuselection:`SALES --> Configuration --> Settings` and activate
+the *Online Signature & Payment* feature.
+
+.. image:: media/getsignaturetovalidate01.png
+    :align: center 
+
+.. note:: 
+ If you are using `quotation templates <https://drive.google.com/open?id=11UaYJ0k67dA2p-ExPAYqZkBNaRcpnItCyIdO6udgyOY>`_,
+ you can also pick a default setting for each template.
+
+Validate an order with a signature
+==================================
+
+When you sent a quotation to your client, they can accept it and sign online instantly.
+
+.. image:: media/getsignaturetovalidate02.png
+   :align: center 
+
+Once signed the quotation will be confirmed and delivery will start.
+
+

sales/send_quotations/invoice_and_deliver_to_different_address.rst

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+===========================================
+Deliver and invoice to different addresses
+===========================================
+
+In Odoo you can configure different addresses for delivery and
+invoicing. This is key, not everyone will have the same delivery
+location as their invoice location.
+
+Activate the feature
+=====================
+
+Go to :menuselection:\`SALES --> Configuration → Settings\` and activate
+the \*Customer Addresses\* feature.
+
+.. image:: media/invoice_and_deliver_to_different_address01.png
+    :align: center 
+
+Add different addresses to a quotation or sales order
+======================================================
+
+If you select a customer with an invoice and delivery address set, Odoo
+will automatically use those. If there’s only one, Odoo will use that
+one for both but you can, of course, change it instantly and create a
+new one right from the quotation or sales order.
+
+.. image:: media/invoice_and_deliver_to_different_address02.png
+    :align: center 
+
+Add invoice & delivery addresses to a customer
+===============================================
+
+If you want to add them to a customer before a quotation or sales order,
+they are added to the customer form. Go to any customers form under
+:menuselection:\`SALES --> Orders→ Customers\`.
+
+From there you can add new addresses to the customer.
+
+.. image:: media/invoice_and_deliver_to_different_address03.png
+    :align: center 
+
+Various addresses on the quotation / sales orders
+=================================================
+
+These two addresses will then be used on the quotation or sales order
+you send by email or print.
+
+.. image:: media/invoice_and_deliver_to_different_address04.png
+    :align: center