[FEATURE] Example emphasizing private subnets and IPV6

[stevenfollis]

Is your feature request related to a problem? Please describe

With recent changes to how AWS charges for IPv4 addresses, it would be useful to have a clear example in ECS Blueprints that demonstrates an architecture that minimizes the need for public IPv4 addresses and emphasizes private subnets, ideally with ipv6.

Describe the solution you'd like

Given that ECS/F requires dual stack ipv6 today, we could show provisioning a VPC with an ipv6 range enabled and how it works with tasks? Fuzzy on how exactly this should work but emphasizing ipv6, and de-emphasizing ipv4 where possible.