Add gobl library to financial libraries list

Added gobl library to the list of financial libraries.

Author: samlown

README.md

@@ -1173,6 +1173,7 @@ _Packages for accounting and finance._
 - [go-finnhub](https://github.com/m1/go-finnhub) - Client for stock market, forex and crypto data from finnhub.io. Access real-time financial market data from 60+ stock exchanges, 10 forex brokers, and 15+ crypto exchanges.
 - [go-money](https://github.com/rhymond/go-money) - Implementation of Fowler's Money pattern.
 - [go-nowpayments](https://github.com/matm/go-nowpayments) - Library for the crypto NOWPayments API.
+- [gobl](https://github.com/invopop/gobl) - Invoice and billing document framework. JSON Schema based. Automates tax calculations and validation, with tooling to convert into global formats.
 - [ledger](https://github.com/formancehq/ledger) - A programmable financial ledger that provides a foundation for money-moving applications.
 - [money](https://github.com/govalues/money) - Immutable monetary amounts and exchange rates with panic-free arithmetic.
 - [ofxgo](https://github.com/aclindsa/ofxgo) - Query OFX servers and/or parse the responses (with example command-line client).