Add AAAA record to shopify.com template

[JLoppert]

Updates shopify.com.website.json template to add an AAAA record to support IPV6.

The IPV6 Address used in the AAAA record is referenced in the Shopify Help Center documentation

• https://help.shopify.com/en/manual/domains/troubleshoot-issues-with-domains#aaaa-not-pointing-to-shopify

cc: @pascal-de-ladurantaye / @snehashah-shopify / @av13t

[pascal-de-ladurantaye]

Feel free to send an email our way for change approval!

[pawel-kow]

It would be good to have confirmation from any of the previous committers to this template @wesbaker @iaserrat @unixcharles