Move section for infrastructure-live repository to the production-grade-aws-account guide

[ina-stoyanova]

Currently, we've got on the CIS compliance benchmark guide the following snippet:

=== Prepare your `infrastructure-live` repository

We've previously described exactly how to prepare your repository in the
link:https://gruntwork.io/guides/foundations/how-to-configure-production-grade-aws-account-structure/#prepare-your-infrastructure-live-repository[Gruntwork Landing Zone guide].
Follow the steps in that section to get your `infrastructure-live` repository set up for the next steps.

Action: This could/should be moved to our production-aws-grade-design guide