[MOV] content/*: move resource files into their related page's directory

Since odoo/documentation#903, the guideline for the location of new
resource (images, downloadable files, RST includes...) files is to place
those inside the directory of the RST page that references them.

For example, if `doc1.rst` has a reference to `image.png` and to
`download.zip`, the file structure should look like this:

├── parent_doc/
│     └── doc1/
│     │     └── image.png
│     │     └── download.zip
│     └── doc1.rst
│     └── doc2.rst
├── parent_doc.rst

Before this commit, most of the resource files were still located inside
'media' directories holding all the resource files referenced by RST
pages located at the same level as these directories. In the example
above, a single 'media' directory would hold all the resource files
referenced by both `doc1.rst` and `doc2.rst`. Doing so prevented us from
figuring out easily which resource file was referenced by which RST page
and, thus, lead to unused resource files piling up in the repository. It
also made it more complicated to define codeowners regex rules because a
team could not simply be assigned to `/some_page.*` but needed to be
assigned to both `/some_page\.rst` and to the location of 'media'.

In order to help new content writers figure out the guideline when
taking examples from other RST pages, this commit retroactively applies
the guideline to existing resource files and 'media' directories. The
left-over resource files that are not referenced by any RST page are
removed.

task-2497965

Part-of: odoo/documentation#2068

content/applications/finance/accounting/getting_started/initial_configuration/chart_of_accounts.rst

@@ -22,7 +22,7 @@ time, they are listed as follows :
 When browsing your Chart of Accounts, you can filter the accounts by number, in the left column, and
 also group them by Account Type.
 
-.. image:: media/chart_of_accounts01.png
+.. image:: chart_of_accounts/chart_of_accounts01.png
    :align: center
    :alt: Group the accounts by type in Odoo Accounting
 
@@ -145,7 +145,7 @@ To display your **Trial Balance** report with your Account Groups, go to :menuse
 --> Reporting --> Trial Balance`, then open the *Options* menu and select **Hierarchy and
 Subtotals**.
 
-.. image:: media/chart_of_accounts02.png
+.. image:: chart_of_accounts/chart_of_accounts02.png
    :align: center
    :alt: Account Groups in the Trial Balance in Odoo Accounting
 

content/applications/finance/accounting/getting_started/initial_configuration/setup.rst

@@ -21,7 +21,7 @@ Accounting onboarding banner
 
 The step-by-step Accounting onboarding banner is composed of four steps:
 
-.. image:: media/setup_accounting_onboarding.png
+.. image:: setup/setup_accounting_onboarding.png
    :align: center
    :alt: Step-by-step onboarding banner in Odoo Accounting
 
@@ -39,7 +39,7 @@ This menu allows you to add your company’s details such as the name, address,
 number, email address, and Tax ID, or VAT number. These details are then displayed on your documents,
 such as on invoices.
 
-.. image:: media/setup_company.png
+.. image:: setup/setup_company.png
    :align: center
    :alt: Add your company's details in Odoo Accounting and Odoo Invoicing
 
@@ -105,7 +105,7 @@ opening balances.
 Basic settings are displayed on this page to help you review your Chart of Accounts. To access all
 the settings of an account, click on the *double arrow button* at the end of the line.
 
-.. image:: media/setup_chart_of_accounts.png
+.. image:: setup/setup_chart_of_accounts.png
    :align: center
    :alt: Setup of the Chart of Accounts and their opening balances in Odoo Accounting
 
@@ -125,7 +125,7 @@ If you have Odoo Accounting installed on your database, you can reach it by goin
 
 The Invoicing onboarding banner is composed of four main steps:
 
-.. image:: media/setup_invoicing_onboarding.png
+.. image:: setup/setup_invoicing_onboarding.png
    :align: center
    :alt: Step-by-step onboarding banner in Odoo Invoicing
 
@@ -155,7 +155,7 @@ automatically adds the company's phone number, email, website URL, and Tax ID (o
 footer, according to the values you previously configured in the :ref:`Company Data
 <accounting-setup-company>`.
 
-.. image:: media/setup_document_layout.png
+.. image:: setup/setup_document_layout.png
    :align: center
    :alt: Document layout configuration in Odoo Invoicing
 

content/applications/finance/accounting/getting_started/process_overview/customer_invoice.rst

@@ -55,10 +55,10 @@ Let's create a customer invoice with following information:
 - Unit Price: 100
 - Taxes: Tax 15%
 
-.. image:: ./media/invoice01.png
+.. image:: customer_invoice/invoice01.png
    :align: center
 
-.. image:: ./media/invoice02.png
+.. image:: customer_invoice/invoice02.png
    :align: center
 
 The document is composed of three parts:
@@ -80,7 +80,7 @@ then moves from the Draft state to the Open state.
 When you have validated an invoice, Odoo gives it a unique number from a
 defined, and modifiable, sequence.
 
-.. image:: ./media/invoice03.png
+.. image:: customer_invoice/invoice03.png
    :align: center
 
 Accounting entries corresponding to this invoice are automatically
@@ -88,7 +88,7 @@ generated when you validate the invoice. You can see the details by
 clicking on the entry in the Journal Entry field in the "Other Info"
 tab.
 
-.. image:: ./media/invoice04.png
+.. image:: customer_invoice/invoice04.png
    :align: center
 
 Send the invoice to customer
@@ -97,7 +97,7 @@ Send the invoice to customer
 After validating the customer invoice, you can directly send it to the
 customer via the 'Send by email' functionality.
 
-.. image:: ./media/invoice05.png
+.. image:: customer_invoice/invoice05.png
    :align: center
 
 A typical journal entry generated from a validated invoice will look
@@ -142,7 +142,7 @@ according to your accounting localisation.
 Create a bank statement from the accounting dashboard with the related
 journal and enter an amount of $100 .
 
-.. image:: ./media/invoice06.png
+.. image:: customer_invoice/invoice06.png
    :align: center
 
 Reconcile
@@ -150,7 +150,7 @@ Reconcile
 
 Now let's reconcile!
 
-.. image:: ./media/invoice07.png
+.. image:: customer_invoice/invoice07.png
    :align: center
 
 You can now go through every transaction and reconcile them or you can mass reconcile with instructions at the bottom.
@@ -159,16 +159,16 @@ After reconciling the items in the sheet, the related invoice will now
 display "You have outstanding payments for this customer. You can
 reconcile them to pay this invoice. "
 
-.. image:: ./media/invoice08.png
+.. image:: customer_invoice/invoice08.png
    :align: center
 
-.. image:: ./media/invoice09.png
+.. image:: customer_invoice/invoice09.png
    :align: center
 
 Apply the payment. Below, you can see that the payment has been added to
 the invoice.
 
-.. image:: ./media/invoice10.png
+.. image:: customer_invoice/invoice10.png
    :align: center
 
 Payment Followup
@@ -189,10 +189,10 @@ will be executed.
 By going to the customer record and diving into the "Overdue Payments"
 you will see the follow-up message and all overdue invoices.
 
-.. image:: ./media/invoice11.png
+.. image:: customer_invoice/invoice11.png
    :align: center
 
-.. image:: ./media/invoice12.png
+.. image:: customer_invoice/invoice12.png
    :align: center
 
 Customer aging report:
@@ -205,7 +205,7 @@ their work.
 Use the aging report to determine which customers are overdue and begin
 your collection efforts.
 
-.. image:: ./media/invoice13.png
+.. image:: customer_invoice/invoice13.png
    :align: center
 
 Profit and loss
@@ -216,7 +216,7 @@ Ultimately, this gives you a clear image of your Net Profit and Loss. It
 is sometimes referred to as the "Income Statement" or "Statement of
 Revenues and Expenses."
 
-.. image:: ./media/invoice14.png
+.. image:: customer_invoice/invoice14.png
    :align: center
 
 Balance sheet
@@ -225,10 +225,10 @@ Balance sheet
 The balance sheet summarizes your company's liabilities,
 assets and equity at a specific moment in time.
 
-.. image:: ./media/invoice15.png
+.. image:: customer_invoice/invoice15.png
    :align: center
 
-.. image:: ./media/invoice16.png
+.. image:: customer_invoice/invoice16.png
    :align: center
 
 For example, if you manage your inventory using the perpetual accounting

content/applications/finance/accounting/getting_started/process_overview/supplier_bill.rst

@@ -21,7 +21,7 @@ When a vendor bill is received, you can record it from :menuselection:`Purchases
 in the Accounting application. As a shortcut,
 you can also use the **New Bill** feature on the accounting dashboard.
 
-.. image:: ./media/vendor_bill05.png
+.. image:: supplier_bill/vendor_bill05.png
    :align: center
 
 To register a new vendor bill, start by selecting a vendor and inputting
@@ -29,7 +29,7 @@ their invoice as the **Vendor Reference**, then add and confirm the product
 lines, making sure to have the right product quantities, taxes and
 prices.
 
-.. image:: ./media/vendor_bill01.png
+.. image:: supplier_bill/vendor_bill01.png
    :align: center
 
 Save the invoice to update the pre tax and tax amounts at the bottom of
@@ -86,7 +86,7 @@ memo field, we recommend you set the vendor invoice number as a
 reference (Odoo will auto fill this field from the from the vendor bill
 if set it correctly).
 
-.. image:: ./media/vendor_bill06.png
+.. image:: supplier_bill/vendor_bill06.png
    :align: center
 
 
@@ -106,7 +106,7 @@ print in checks in batches.
 If you have checks to print, Odoo's accounting dashboard acts as a to do
 list and reminds you of how many checks you have left to be printed.
 
-.. image:: ./media/vendor_bill02.png
+.. image:: supplier_bill/vendor_bill02.png
    :align: center
 
 By selecting the amount of checks to be printed, you can dive right into
@@ -117,7 +117,7 @@ select them all) and set the action to **Print Checks**. Odoo will ask you
 to set the next check number in the sequence and will then print all the
 checks at once.
 
-.. image:: ./media/vendor_bill03.png
+.. image:: supplier_bill/vendor_bill03.png
    :align: center
 
 Reporting
@@ -131,7 +131,7 @@ you can use the **Aged Payable** report, under the reporting menu, (in
 :menuselection:`Reporting --> Business Statement --> Aged payable`) to get a visual of all of
 your outstanding bills.
 
-.. image:: ./media/vendor_bill04.png
+.. image:: supplier_bill/vendor_bill04.png
    :align: center
 
 From here, you can click directly on a vendors name to open up the