[ADD] point_of_sale: How to setup Point of Sale Restaurant

https://docs.google.com/document/d/1c0fE28u1NscVwiu8imkJyFEmHL4QR2UlghwtomdrChc/edit#heading=h.teahchhagxca

point_of_sale/restaurant.rst

@@ -5,6 +5,7 @@ Advanced Restaurant Features
 .. toctree::
    :titlesonly:
 
+   restaurant/setup
    restaurant/table
    restaurant/split
    restaurant/print

point_of_sale/restaurant/setup.rst

@@ -0,0 +1,40 @@
+======================================
+How to setup Point of Sale Restaurant?
+======================================
+
+Go to the **Point of Sale** application, 
+:menuselection:`Configuration --> Settings`
+
+.. image:: media/setup01.png
+    :align: center
+
+Enable the option **Restaurant: activate table management** and
+click on **Apply**.
+
+.. image:: media/setup02.png
+    :align: center
+
+Then go back to the **Dashboard**, on the point of sale you want to use in
+restaurant mode, click on :menuselection:`More --> Settings`.
+
+.. image:: media/setup03.png
+    :align: center
+
+Under the **Restaurant Floors** section, click on **add an item** 
+to insert a floor and to set your PoS in restaurant mode.
+
+.. image:: media/setup04.png
+    :align: center
+
+Insert a floor name and assign the floor to your point of sale.
+
+.. image:: media/setup05.png
+    :align: center
+
+Click on **Save & Close** and then on **Save**. 
+Congratulations, your point of sale is
+now in Restaurant mode. The first time you start a session, you will
+arrive on an empty map. 
+
+.. seealso::
+    * :doc:`table`