[IMP] point_of_sale: remove start category feature from pos

In this commit:
==============
The "Start Category" feature has been removed from the Point of Sale.
This feature is now redundant due to the existing "Restrict Category" feature,
which provides similar functionality by limiting the available categories in POS

Task- 4405337

closes odoo/documentation#11582

Signed-off-by: Loredana Perazzo (lrpz) <lrpz@odoo.com>

content/applications/sales/point_of_sale/configuration.rst

@@ -77,25 +77,11 @@ the :guilabel:`Point of Sale` tab and fill in the :guilabel:`Category` field und
 .. image:: configuration/form-pos-category.png
    :alt: Point of Sale tab of a product form to add a PoS product category
 
-Adapt the POS interface
------------------------
-
-Start category
-~~~~~~~~~~~~~~
-
-You can select one product category to display when :ref:`opening a POS session
-<pos/session-start>`. To configure it, go to your :ref:`POS settings <configuration/settings>` and
-select a PoS category from the dropdown menu of the :guilabel:`Start Category` field within the
-:guilabel:`Product & PoS categories` section.
-
-.. image:: configuration/start-category.png
-   :alt: Setting to set up the start category feature
-
 Restrict categories
-~~~~~~~~~~~~~~~~~~~
+-------------------
 
-You can also limit the categories displayed on your POS interface. To achieve this, go to your
-:ref:`POS settings <configuration/settings>` and choose the specific categories to display in the
+You can limit the categories displayed on your POS interface. To achieve this, go to your :ref:`POS
+settings <configuration/settings>` and choose the specific categories to display in the
 :guilabel:`Restrict Categories` field within the :guilabel:`Product & PoS categories` section.
 
 .. image:: configuration/restrict-category.png