Update resoures of some spec/standard

dev/resources/iso-normes/QR code for invoices.txt

@@ -0,0 +1,13 @@
+List of QR Code format we found on some invoices
+------------------------------------------------
+
+
+* For SEPA QR payment Code format (Europe)
+------------------------------------------
+https://en.wikipedia.org/wiki/EPC_QR_code#Generators
+
+
+
+* For ZATCA QR Code format (Saudi Arabia)
+-----------------------------------------
+https://www.pwc.com/m1/en/services/tax/me-tax-legal-news/2021/saudi-arabia-guide-to-develop-compliant-qr-code-for-simplified-einvoices.html

dev/resources/iso-normes/address_format.txt

@@ -1,3 +1,5 @@
+Address format
+
 https://bitboost.com/ref/international-address-formats.html#Formats
 
 https://www.upu.int/en/Postal-Solutions/Programmes-Services/Addressing-Solutions

dev/resources/iso-normes/locales.txt

@@ -1,3 +1,5 @@
+Date and number format
+----------------------
 
 For languages:
 https://icu4c-demos.unicode.org/icu-bin/icudemos - Locale Explorer -> Error 404

dev/resources/iso-normes/world_tax_rates.txt

@@ -1,3 +1,6 @@
+VAT Rates
+---------
+
 http://www.taxrates.cc/index.html
 https://en.wikipedia.org/wiki/List_of_countries_by_tax_rates