AWS best practices

Disclaimer:  I think the formatting is ok here (famous last words) :8ball: 

This is a PR for a docs page which discusses some best practices and how-to for using Ansible with AWS.  This should be a living document, we should encourage folks to add to this and share how they are using Ansible with AWS / a-n-other cloud (since majority of it is generic).  I still need to add details on usage / use case for each module.  I propose adding this information later once we find a place for this base document.