[REM] *: remove all demo.action buttons from the user documentation

*: accounting, inventory, purchase

As these buttons points to demo.odoo.com, it is outdated very quickly
and leads to weird results were a button on the 10.0 documentation
points to demo.odoo.com that runs 13.0 or no longer exists.

purchase/purchases/rfq/create.rst

@@ -25,12 +25,6 @@ Select your supplier in the **Vendor** menu, or create it on-the-fly by
 clicking on **Create and Edit**. In the **Order Date** field, select
 the date to which you wish to proceed to the actual order.
 
-.. demo:fields:: purchase.purchase_rfq
-
-.. demo:action:: purchase.purchase_rfq
-
-   View *Request for Quotation* in our Online Demonstration
-
 In **Products**, click on Add an item. Select the product you wish to order
 in the **Product** menu. Specify the **Quantity** by inserting the
 number and selecting the unit of measure. In the **Unit Price** field,
@@ -40,8 +34,6 @@ expected delivery date in the Scheduled Date field. Click on **Save**, then
 **Print Rfq** or **Send Rfq by email** (make sure an email address is specified
 for this supplier or enter a new one).
 
-
-
 .. image:: ./media/image08.png
    :align: center