Add AWS installation docs
What does this MR do?
A new detailed doc https://docs.gitlab.com/ce/install/aws intended to replace the old AWS info https://about.gitlab.com/aws/
Related issues
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/49501 Follow-up https://gitlab.com/gitlab-org/gitlab-ce/issues/53606
Review app: http://review-docs-docs-rx9mzd.178.62.207.141.xip.io/ce/install/aws/
Edited by Mike Lewis