Docs: highlight multiple compilation targets support in Wing docs

Summary

Highlight multiple compilation targets support in Wing docs

Feature Spec

A FAQ we get is why does Wing compile to Terraform, not CloudFormation. Our documentation should highlight the fact that we currently have the Terraform target available, but plan to add CloudFormation target in the future.

Use Cases

Answer FAQ by people who come across Wing for the first time.

Implementation Notes

We should add an FAQ + consider other ways to communicate that through Wing docs.

Component

Documentation