Restructure Self Hosted Docs around Types of documentation

[lucasvaltl]

Requires https://github.com/gitpod-io/website/issues/1547

Goal:

Group self-hosted docs around types of documentation rather than themes.

Implement the following structure

(This assumes the existence of reference architectures and no new pages):

• Getting Started

  • Local preview installation method (assumes Epic: Local preview "installation" method #9075 is completed)

• Installation Guides

  • How to set up the Prod Reference Architecture (assumes https://github.com/gitpod-io/website/pull/2106/files is merged)
  • Install Gitpod on an Air Gappped Network

• Operational Guides

  • https://www.gitpod.io/docs/self-hosted/latest/monitoring (rename to How to Monitor GItpod)
  • How to update gitpod

• Troubleshooting

  • Troubleshooting Self-Hosted Gitpod (renamed to How to send support bundles?)
  • Gitpod Provided Support Patches

• Background

  • TLS configuration for Gitpod Self-Hosted

• Reference

  • Merge Internal Compatibility Matrix with the one in the docs #10126: Create one page that combines cluster set-up with required components.
  • Telemetry gathered

Existing pages that would be deprecated

• Getting started installation guide (to be replaced by reference architecture + local preview installation method.
• Manual installation of Gitpod using the Gitpod Installer (not a page) - we want you to use the default installation method (replicated)