[ADD] accounting: new shared accounts feature documentation

In 18.0 was the shared accounts feature added to Odoo but the documentation
doesn't contain any data related to it. This commit brings information about
said feature in the documentation.

task-4485674

Author: Megaaaaaa

content/applications/finance/accounting.rst

@@ -82,9 +82,11 @@ Multi-company
 =============
 
 Several companies can be managed within the same database. Each company has its :doc:`chart of
-accounts <accounting/get_started/chart_of_accounts>`, which is also useful to generate consolidation
-reports. Users can access several companies but can only work on a single company's accounting at a
-time.
+accounts <accounting/get_started/chart_of_accounts>`, but it is possible to share accounts in
+between them for scenarios in which such a configuration would be required.
+
+.. seealso::
+   :ref:`Shared Accounts Feature <coa_shared_accounts>`
 
 Multi-currency environment
 ==========================

content/applications/finance/accounting/get_started.rst

@@ -179,6 +179,7 @@ Get started with Stripe and enable secure integrated credit and debit card payme
 .. seealso::
    * :doc:`bank`
    * :doc:`get_started/chart_of_accounts`
+   * :doc:`get_started/shared_accounts`
    * :doc:`bank/bank_synchronization`
    * :doc:`../fiscal_localizations`
    * `Odoo Tutorials: Accounting and Invoicing - Getting started [video]
@@ -189,6 +190,7 @@ Get started with Stripe and enable secure integrated credit and debit card payme
 
    get_started/cheat_sheet
    get_started/chart_of_accounts
+   get_started/shared_accounts
    get_started/multi_currency
    get_started/avg_price_valuation
    get_started/tax_units

content/applications/finance/accounting/get_started/chart_of_accounts.rst

@@ -169,6 +169,23 @@ To do so, check the :guilabel:`Allow Reconciliation` box in the account's settin
 .. image:: chart_of_accounts/chart-of-accounts-reconciliation.png
    :alt: Allow reconciliation for accounts in Odoo Accounting
 
+.. _coa_shared_accounts:
+
+Shared Accounts
+---------------
+
+This feature allows you to create a single account for a specific purpose and share it between
+multiple companies. It is especially useful for multi-company environments in which a similar
+account might be used across different companies.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_accounting.png
+   :alt: Shared accounts feature in Odoo Accounting
+
+.. note::
+   Check the :doc:`Shared Accounts <shared_accounts>` page for more information on the
+   :ref:`benefits of that feature <shared_accounts_benefits>` and :ref:`how to configure it
+   <setting_up_shared_accounts>`.
+
 Deprecated
 ----------
 

content/applications/finance/accounting/get_started/shared_accounts.rst

@@ -0,0 +1,157 @@
+===============
+Shared Accounts
+===============
+
+In Odoo, it is possible to share accounts between multiple companies. This feature is particularly
+useful for businesses that operate under a **multi-company structure** and might benefit from a
+**unified chart of accounts**.
+
+In order to setup said feature, two ways are available: Either the :ref:`basic setup
+<setting_up_shared_accounts>` or using the :ref:`merge tool <merge_tool>`.
+
+In the same way the feature is accompanied by a merging tool that helps already established
+multi-company environments use the the new shared accounts feature, an :ref:`unmerge tool
+<unmerge_tool>` is also available for if you ever want to stop using the feature.
+
+.. _shared_accounts_benefits:
+
+Benefits of Shared Accounts
+===========================
+
+1. Lighter load of accounts to handle
+-------------------------------------
+
+The main benefit of the shared accounts feature is to **reduce the amount of accounts** that have
+to be handled by the main accountant of a multi-company environment.
+
+.. example::
+   Environments that have two companies using the generic chart of accounts of the same country
+   used to have each accounts of that chart twice. With the shared accounts feature, it is possible
+   to have a single version of each of those accounts.
+
+2. Simplified and Cleaner Reporting
+-----------------------------------
+
+When auditing reports, the shared accounts feature grants a **lighter version of the reports**
+while **keeping all the data visible and accessible**. This makes it easier to understand and
+manage the accounts.
+
+.. example::
+   Auditing amounts in the balance sheet report of a company using a shared account with one of its
+   child companies and grouping by account used to show two groups for the two accounts that share
+   the same purpose. Now they are shown in the same group and are differentiable using the company
+   they are used in.
+
+3. Micro and Macro Management
+-----------------------------
+
+For the main companies as much as the last child company of a branch, using the shared accounts
+feature allows accountants to **handle the accounts at the level they need to**. This means that
+the main accountant can manage the accounts of the whole group while the accountant of a child
+company can manage the accounts of that company **without having to worry** about the impact it
+might have on the other companies.
+
+.. example::
+   Even though the account is shared and is the same record in the database for all companies, its
+   code in any company can be modified without affecting the other companies granting a lot of
+   flexibility in the management of the accounts.
+
+.. _setting_up_shared_accounts:
+
+Setting Up Shared Accounts
+==========================
+
+Enable Multi-Company
+--------------------
+
+To enable account sharing, you first need to enable the multi-company feature in Odoo. This can be
+done by simply making sure you have multiple companies setup in your Odoo database.
+
+Configure Shared Accounts
+-------------------------
+
+Once multi-company is enabled, you can configure shared accounts by going to an account you wish to
+share between companies. Head into the :guilabel:`Mapping` tab and enter the code you want for the
+account for each desired company.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_mapping.png
+   :alt: Configuring company relative codes for a shared account in Odoo Accounting
+
+Afterwards, you can head back to the :guilabel:`Accounting` tab and add your second company to the
+list of companies this account is available for.
+
+.. image:: shared_accounts/shared_accounts_configure_shared_accounts_accounting.png
+   :alt: Adding a company to a shared account in Odoo Accounting
+
+.. _merge_tool:
+
+Merge Tool
+==========
+
+Use cases
+---------
+
+The merging tool is there to simplify the process of creating shared accounts. This tool is
+particularly useful when you have an **already setup multi-company environment** in which you were
+using separate accounts that you now want to merge.
+
+Steps
+-----
+
+To use the merge tool, you need to select all the companies that have an account you want to merge
+in the company selector in the top right corner of the screen.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_select_companies.png
+   :alt: Selecting all companies that have accounts to be merged.
+
+You can then select all the account that are to be merged, click the :guilabel:`Actions` button,
+and select the :guilabel:`Merge accounts` option in the drop-down.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_merge_action.png
+   :alt: Selecting the accounts to merge and the tool in the options.
+
+You will then enter a confirmation wizard where you can confirm the operation. Once all is set,
+you can click the :guilabel:`Merge` button to complete the process.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_confirmation_wizard.png
+   :alt: Confirmation wizard for the Merge Tool of the shared accounts feature.
+
+In the end, the selected accounts will be merged into a single shared account that is available for
+all the selected companies in the same way it would have been if the account had only been created
+on a single company and then configured to be shared like in the :ref:`basic setup
+<setting_up_shared_accounts>`.
+
+.. image:: shared_accounts/shared_accounts_merge_tool_result.png
+   :alt: Result of the Merge Tool of the shared accounts feature.
+
+.. _unmerge_tool:
+
+Unmerge Tool
+============
+
+Use cases
+---------
+
+At the opposite end of the spectrum, the unmerge tool is there to simplify the process of stopping
+to share specific accounts. This tool finds its use when you have shared accounts that you want to
+**dissociate from certain companies** without losing the data that they contain.
+
+Steps
+-----
+
+Using any of the companies that have a shared account, it is possible to select it and unmerge it
+using the :guilabel:`Unmerge account` option in the :guilabel:`Actions` menu.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_unmerge_action.png
+   :alt: Selecting an account to unmerge and the tool in the options.
+
+This will open a confirmation window listing all the accounts that will be created.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_confirmation_wizard.png
+   :alt: Confirmation wizard for the Unmerge Tool of the shared accounts feature.
+
+In the end, each of the companies that had a code configured on the shared account will have a new
+account linked to no other company.
+
+.. image:: shared_accounts/shared_accounts_unmerge_tool_result.png
+   :alt: Result of the Unmerge Tool of the shared accounts feature.