Add snippet for javascript and python on Create payment request api endpoint

[Alexterieur0]

add a response sample : {'uuid': '6cecd395-92bf-4da6-8f2c-0611940ea0bb', 'label': 'For the restaurant', 'currency': 'BTC', 'payment_split': '0.0', 'requires_customer_email': False, 'requires_delivery_address': False, 'amount': '0.01', 'created_at': '1688138855', 'updated_at': '1688138855'}

Warning, when one request bitcoin, payment split must be 0.