Update production deployment guides

We want to revamp the walkthrough to describe the new service catalog way to deploy your infrastructure.

- [ ] Deploy a production-grade AWS account structure using Gruntwork AWS Landing Zone PR: #439
- [ ] Deploy a production-grade VPC on AWS
- [ ] Deploy a production-grade Kubernetes cluster on AWS

Resolved discussion

## Keep the old docs? [No]
Is there any need to keep the old guides around for posterity? So rather than making changes here, is it better to write a whole new guide that's largely based on this? /cc @yorinasub17 @brikis98 @bwhaley @zackproser I'm leaning toward not keeping the old guides around as they are, but would like to hear alternative arguments.

## Grouping the walkthrough docs [No change]
Once published/updated, I was thinking we could group all the guides together under a "Using the Service Catalog" category of tutorials, and publish announcements (blog posts) as they come out.
* Deploy a production grade AWS account structure using Gruntwork AWS Landing Zone
* VPC
* Kubernetes

Currently these are all under different headings:

Is it better to group these walkthroughs differently? [No]