docs: add Zero Trust implementation guide (#526)

* docs: add Zero Trust implementation guide

* minor text and formatting fixes

* various improvements to the zero trust guide

* Added links to other relevant docs pages

* docs: improve Zero Trust implementation guide

- Add guide to navigation menu
- Rewrite section 5.2 on routing peer traffic direction for clarity
- Add documentation links throughout (Networks, Access Control, DNS,
  Control Center, Setup Keys, IdP sync, Traffic Events, Event Streaming)
- Add internal section and appendix cross-references
- Remove "Subject" terminology, replace with "source groups" and
  clearer user/peer terminology
- Expand acronyms on first use (IdP, SSO, MFA, SIEM, CIDR, VPC, etc.)
- Add explanations for technical concepts (masquerading, overlay networks,
  NAT traversal, protocols, ports)
- Enhance firewall rules section with service explanations and FAQ link
- Improve worked examples with port and protocol context
- Add command-line tool explanations for troubleshooting
- Make guide more accessible for junior network admins and students

* Minor changes and adjustments.

* Add various diagrams

* Add dashboard settings best practices section

* Improve zero trust guide with MDX components, examples, and clarity

  - Add Note/Warning MDX components replacing markdown blockquotes
  - Add TURN service rules to firewall configuration section
  - Add JSON API example for policy creation
  - Improve three-tier app diagram with box-drawing characters
  - Add Networks vs legacy Network Routes warning for Zero Trust
  - Add CIDR posture check limitation note (iOS/Android unsupported)
  - Add DNS forwarder port change note (v0.59.0+)
  - Add lazy connections feature limitations and version requirements
  - Add Users view to Control Center documentation
  - Convert verification checklists to Note components
  - Fix grammar throughout (serial commas, hyphenation consistency)
  - Improve term definitions and service descriptions

* Update zero trust guide to enhance clarity and provide outbound port references

- Replace detailed outbound allowlist rules with links to FAQ and self-hosted guide for port requirements
- Minor adjustments to lazy connections feature description for consistency

---------

Co-authored-by: Brandon Hopkins <76761586+TechHutTV@users.noreply.github.com>
Co-authored-by: Ashley Mensah <ashleyamo982@gmail.com>

src/components/NavigationDocs.jsx

@@ -346,6 +346,7 @@ export const docsNavigation = [
             { title: 'Site-to-Site and Site-to-VPN', href: '/use-cases/setup-site-to-site-access' },
             { title: 'Serverless and NetBird', href: '/use-cases/netbird-on-faas' },
             { title: 'Routing peers and Kubernetes', href: '/use-cases/routing-peers-and-kubernetes' },
+            { title: 'Implement Zero Trust with NetBird', href: '/use-cases/implement-zero-trust' },     
             { title: 'NetBird Client on AWS ECS', href: '/use-cases/examples' },
             { title: 'NetBird on Mikrotik Router', href: '/use-cases/client-on-mikrotik-router' },
             { title: 'Distributed AI on Kubernetes', href: '/use-cases/distributed-multi-cloud-ai-argocd-microk8s-vllm' },