[ADD] Accounting: Admonition Block Sunset TaxCloud

closes odoo/documentation#5978

Signed-off-by: Zachary Straub (zst) <zst@odoo.com>

content/applications/finance/accounting/taxes.rst

@@ -296,7 +296,7 @@ directly to a product line.
 
   - :doc:`taxes/fiscal_positions`
   - :doc:`taxes/B2B_B2C`
-  - :doc:`taxes/taxcloud`
+  - :doc:`taxes/taxcloud` (decommissioning TaxCloud integration in Odoo 17+)
   - :doc:`reporting/tax_returns`
 
 .. toctree::

content/applications/finance/accounting/taxes/fiscal_positions.rst

@@ -107,5 +107,5 @@ To manually select which Fiscal Position to use for a new Sales Order, Invoice,
 .. seealso::
 
   * :doc:`../taxes`
-  * :doc:`taxcloud`
+  * :doc:`taxcloud` (decommissioning TaxCloud integration in Odoo 17+)
   * :doc:`B2B_B2C`

content/applications/finance/accounting/taxes/taxcloud.rst

@@ -2,9 +2,17 @@
 TaxCloud integration
 ====================
 
+.. warning::
+   The Odoo TaxCloud integration has begun its decommissioning, starting in Odoo 17. New
+   installations are prohibited in Odoo 17. In Odoo 18, the TaxCloud module(s) will **not** exist at
+   all. Odoo recommends the use of the Avatax platform, instead.
+
+.. seealso::
+   :doc:`avatax`
+
 TaxCloud calculates the sales tax rate in real time for every state, city, and special jurisdiction
-in the United States. It keeps track of which products are exempt from sales tax and in which states
+in the United States. It keeps track of which products are exempt from sales tax, and in which
-each exemption applies.
+states each exemption applies.
 
 TaxCloud registration
 =====================

content/applications/sales/sales/amazon_connector/manage.rst

@@ -91,7 +91,7 @@ the Amazon backend before creating the invoice in Odoo.
 .. note::
    For :doc:`TaxCloud <../../../finance/accounting/taxes/taxcloud>` users: invoices created from
    Amazon sales orders are **not** synchronized with TaxCloud, since Amazon already includes them in
-   its own tax report to TaxCloud.
+   its own tax report to TaxCloud. (decommissioning TaxCloud integration in Odoo 17+)
 
 Register payments
 -----------------