Deploy Sourcegraph in High-Security Environments

[IAmHughes]

This PR adds a deploy reference for setting up Sourcegraph in high-security environments.

• Problem Statement: Currently the Sourcegraph documentation for deploying can have a number of splitting paths making it hard to navigate, and there is limited information on specific requirements when deploying in a high-security environment (such as air gapped deployments)
• Proposed Solution: By creating references like this, the CE/CTE team can hand out a reference PDF (converted from this source controlled markdown file) which assists Sourcegraph Admins in navigating through our documentation in order to properly create their clusters and deploy Sourcegraph to them.
  • Why this?: This is to serve as a specific use-case reference (deploying in a high-security environment) and is not a replacement for official documentation, but a map to the documentation for this use case. This balances the technical debt involved with maintaining detailed documentation and having two sources of truth with a short, easily digestible map to the source of truth (official documentation). This is also a short, 1 pager, that can be easily sorted through for reference.

Would love your 👀 and a 👍 or 💬 letting me know your thoughts 💭. I'm very open to iterating on these more of course but want to get this deliverable pushed for now and hopefully as doc improvements come, we can iterate from there with minimal maintenance overhead (technical debt).