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.