[ADD] accounting: Mexico - Accounting Localization

https://docs.google.com/document/d/17dRCx09_TjJepXjvfXWmb_UMdoBYmP_63ztvv7qq6nk/edit#heading=h.2cgkkd8178p5

accounting/localizations.rst

@@ -6,3 +6,4 @@ Localizations
    :titlesonly:
 
    localizations/switzerland
+   localizations/mexico

accounting/localizations/mexico.rst

@@ -0,0 +1,111 @@
+==============================
+Mexico Accounting Localization
+==============================
+
+Configuration 
+~~~~~~~~~~~~~~
+
+First, install the Mexican Accounting Localization. For this, go in Apps
+and search for Mexico. Then click on *Install*.
+
+.. image:: media/mexico01.png
+   :align: center
+
+.. tip::
+   When creating a database from www.odoo.com, if you choose Mexico
+   as country when creating your account, the mexican localization will be
+   automatically installed.
+
+Accounting Reports
+~~~~~~~~~~~~~~~~~~
+
+Some specific reports have been added for the Mexican accounting
+localization :
+
+-  DIOT
+
+-  COA
+
+-  Trial Balance
+
+Electronic Invoices (CDFI format)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When sending a customer invoice by email, there is an option to join the
+xml file of the invoice to your email (CDFI format). To activate this
+setting, go in accounting > settings and activate the Mexican Electronic
+Invoicing.
+
+.. image:: media/mexico02.png
+   :align: center
+
+
+Invoices Certification
+~~~~~~~~~~~~~~~~~~~~~~
+
+With the Odoo Mexican Localization, certify your customer invoices.
+
+Create your customer invoice and simply send it to a PAC. The PAC will
+sign the invoice and send it back to you but also send the invoice to
+the SAT. Your customer is able to check on the SAT if your invoice is
+well valid before paying it.
+
+Configuration
+^^^^^^^^^^^^^
+
+First, make sure that your company is configured with the correct data.
+Go in :menuselection:`Settings --> Users --> Companies`
+and enter a valid address and VAT for
+your company. Don’t forget to define a mexican fiscal position on your
+company’s contact.
+
+.. tip::
+   If you want to test the Mexican Localization, you can copy the
+   below configuration.
+
+.. image:: media/mexico03.png
+   :align: center
+
+To configure the EDI with the **PACs**, you can go in
+:menuselection:`Accounting --> Settings --> Electronic Invoicing (MX)``.
+You can choose a PAC within the`list of supported PACs and then enter
+your PAC username and PAC password.
+
+.. image:: media/mexico04.png
+   :align: center
+
+.. tip::
+   If you ticked the box *MX PAC test environment* there is no need
+   to enter a PAC username or password.
+
+You then have to enter your **SAT Certificates**. You will have to
+upload your certificate, your certificate key and type your certificate
+password.
+
+.. image:: media/mexico05.png
+   :align: center
+
+.. |download_mexico_certificate_cer| image:: ../../_static/banners/download-icon.png
+      :alt: Certificate
+      :target: ../../_static/files/certificate.cer
+
+.. |download_mexico_certificate_key| image:: ../../_static/banners/download-icon.png
+      :alt: Certificate Key
+      :target: ../../_static/files/certificate.key
+
+.. tip::
+   Here is a SAT certificate you can use if you want to test the
+   Mexican Accounting Locatization.
+
+   - :ref:`Certificate:` |download_mexico_certificate_cer|
+   - :ref:`Certificate Key:` |download_mexico_certificate_key|
+   - Certificate password : 12345678a
+
+Process
+^^^^^^^
+
+Create a customer invoice and validate it. Now you can click on *Action*
+and *Update PAC status*. Your invoice status will be updated.
+
+.. image:: media/mexico06.png
+   :align: center