Add missing field in customer attributes

[a-spn]

Adding the field 'urls' in CustomerAttributes, according to the official documentation.

https://docs.lemonsqueezy.com/api/customers#the-customer-object

Mapping this field into a "map[string]string" seemed to me to be the best option (shorter and more readable + only one field in the sub-object for the moment). If it's preferable, I can create another structure to parse the field "urls" returned by the lemonsqueezy API.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.04%. Comparing base (9a405ae) to head (d60022c).

❗ Current head d60022c differs from pull request most recent head 5ff4fd4. Consider uploading reports for the commit 5ff4fd4 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #23   +/-   ##
=======================================
  Coverage   81.04%   81.04%           
=======================================
  Files          23       23           
  Lines         575      575           
=======================================
  Hits          466      466           
  Misses         56       56           
  Partials       53       53           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[a-spn]

Thank you for your feedback, I replaced the field with an inline struct.

[AchoArnold]

Thanks @a-spn