021_product_pricing.md: Few notes for the future

Author: adriendupuis

docs/trainings/commerce/pim/021_product_pricing.md

@@ -6,3 +6,21 @@ page_type: training
 
 [`ibexa_format_price`](https://doc.ibexa.co/en/latest/templating/twig_function_reference/product_twig_functions/#ibexa_format_price)
 TODO: This is defined in vendor/ibexa/product-catalog/src/bundle/Twig/PriceExtension.php  
+
+## Regions and VAT
+
+### PIM configuration
+
+https://doc.ibexa.co/en/latest/pim/pim_configuration/#vat-rates
+
+### Product type configuration
+
+https://doc.ibexa.co/en/latest/pim/enable_purchasing_products/#vat-rates
+
+https://doc.ibexa.co/projects/userguide/en/latest/pim/product_types/
+
+https://doc.ibexa.co/projects/userguide/en/latest/pim/create_product_types/
+
+## Custom pricing
+
+TODO: exercise with custom prices for retailers.