Add company customer_vat_code_id / supplier_vat_code_id

Author: sunsations

sections/companies.md

@@ -166,7 +166,8 @@ Additional fields just for companies of type customer:
 
 - **currency\*** – "EUR"
 - **identifier\*** – "K-123" (only mandatory if not automatically assigned)
-- **customer_tax** – 19.0
+- **customer_vat_code_id** – 123 (takes precedence over customer_tax)
+- **customer_tax** – 19.0 (deprecated, when vat_code_id is set)
 - **default_invoice_due_days** – 20 (use **invoice_due_days** to set a value for a company)
 - **debit_number** – 10000 if bookkeeping is enabled
 
@@ -175,7 +176,8 @@ Additional fields just for companies of type supplier:
 - **bank_owner** – name of the account holder (if deviating from the supplier name)
 - **iban** – CH3908704016075473007
 - **bank_bic** – POFICHBEXXX
-- **supplier_tax** – 19.0
+- **supplier_vat_code_id** – 123 (takes precedence over supplier_tax)
+- **supplier_tax** – 19.0 (deprecated, when vat_code_id is set)
 - **default_invoice_due_days** – 20 (use **invoice_due_days** to set a value for a company)
 - **credit_number** – 70000 if bookkeeping is enabled