[MOV] accounting: restructuration of the accounting documentation

This commit improves the structure of the accounting documentation by
- reducing the levels necessary to reach the information
- grouping some docs
- moving content to their parent category page (content in all levels)
- renaming some sections to reflect the structure of the app better

task-3330093

closes odoo/documentation#4477

Signed-off-by: Castillo Jonathan (jcs) <jcs@odoo.com>

content/applications/finance/accounting/customer_invoices/epc_qr_code.rst

@@ -0,0 +1,69 @@
+============
+EPC QR Codes
+============
+
+European Payments Council Quick Response Code,
+or **EPC QR Code**, are two-dimensional barcodes
+that customers can scan with their **mobile banking
+applications** to initiate a **SEPA Credit Transfer
+(SCT)**, and pay their invoices instantly.
+
+In addition to bringing ease of use and speed,
+it greatly reduces typing errors that would potentially
+make for payment issues.
+
+.. note::
+   This feature is only available in several European
+   countries such as Austria, Belgium, Finland, Germany,
+   and The Netherlands.
+
+Configuration
+=============
+
+Go to :menuselection:`Accounting --> Configuration --> Settings`
+and activate the **SEPA QR Code** feature.
+
+.. image:: epc_qr_code/epc_qr_code01.png
+   :align: center
+
+Configure your Bank Account’s journal
+-------------------------------------
+
+Make sure that your *Bank Account* is correctly configured
+on Odoo with your IBAN and BIC.
+
+To do so, go to :menuselection:`Accounting --> Configuration
+--> Journals`, open your *bank journal*, then fill out the
+*Bank Account* and *Bank* under the *Bank Account* tab.
+
+.. image:: epc_qr_code/epc_qr_code02.png
+   :align: center
+
+Issue Invoices with EPC QR Codes
+================================
+
+EPC QR Codes are added automatically to your invoices, as
+long as you issue them to customers that are located in a
+country where this feature is available.
+
+Go to :menuselection:`Accounting --> Customers --> Invoices`,
+and create a new invoice.
+
+Before posting it, open the *Other Info* tab. Odoo automatically
+fills out the *Bank Account* field with your IBAN.
+
+Make sure that the account indicated is the one you want to use to
+receive your customer’s payment as Odoo uses this field to generate
+the EPC QR Code.
+
+.. image:: epc_qr_code/epc_qr_code03.png
+   :align: center
+
+.. tip::
+   If you want to issue an invoice without an EPC QR Code,
+   remove the IBAN indicated in the *Bank Account* field,
+   under the *Other Info* tab of the invoice.
+
+.. seealso::
+   * :doc:`../bank`
+   * `Odoo Academy: QR Code on Invoices for European Customers <https://www.odoo.com/r/VuU>`_