The reference architecture neglected to mention ACLs and Sentinel
policies are the exception to "no data is shared between regions."

- Revised "What is Nomad" copy
- Added "Key Features" section with links to task drivers & device plugins with lift-and-shift from README
- Added "Who Uses Nomad" section with users, talks, blog posts
- Removed Hadoop YARN, Docker Swarm, HTCondor from comparisons
- Revamped Guides section
- Inserted "Installing Nomad", "Upgrading", "Integrations" as persistent in Guides navbar
- Split Installing Nomad into two paths for users (one for Sandbox with "Quickstart", one for Production)
- Surfaced "Upgrading" and "Integrations" section from documentation
- Changed "Job Lifecycle" section into "Deploying & Managing Applications"
- Reworked "Operations" into "Operating Nomad"
- Reworked "Security" into "Securing Nomad"
- Segmented Namespaces, Resource Quotas, Sentinel into "Governance & Policy" subsection
- Reworked "Spark integration" into its own "Analytical Workloads" section

Change product_version frontmatter to ea_version and increase to 0.9

* Add Nomad RA

* Add deployment guide and nav

* Deployment Guide update

* Minor typo fixes

* Update diagrams

* Fixes for review

* Link fixes and typo fix

* Edits following review

- Update image text from "zone" to "datacenter" to match Nomad terminology
- Clean up text based on Preetha's feedback

* Text updates

Based on feedback from Rob

* Update diagrams

* fixing spelling

* Add suggestions from Preetha and Omar