Improve Support Environments page to be more inclusive of ALL platforms & deployments

[akeller]

Improve C8 Supported Environments page like following:

• The page should include / or at least clearly link all our requirements. The idea is that this page is the central entry point to discover all the must-requirements to run Camunda 8 fully supported
• Examples that are missing / hard to discover:
  • OpenShift support is not discoverable on the central page but only on a subpage: https://docs.camunda.io/docs/self-managed/platform-deployment/helm-kubernetes/platforms/redhat-openshift/
  • Volume performance requirements for different environments are only discoverable via the subpages. Example: https://docs.camunda.io/docs/self-managed/platform-deployment/helm-kubernetes/platforms/microsoft-aks/#volume-performance

This information should be presented as the minimum requirements to run Self Managed.

From internal thread - https://camunda.slack.com/archives/C06HE33GX9R/p1707472795152039

### Tasks
- [x] Rework form-js info
- [x] Remove older, unsupported versions of Zeebe from matrix
- [x] List and directly link to supported Kubernetes platforms
- [ ] Identify content to move to reusable components
- [ ] https://github.com/camunda/camunda-docs/issues/3369
- [ ] https://github.com/camunda/camunda-docs/issues/3370
- [ ] https://github.com/camunda/developer-experience/issues/264

[akeller]

Open questions:

• OpenShift gaps
  • Starting config recommendations?
  • Volume performance info?
• Are the volume performance docs the minimum requirements? Average requirements? Can we say more about how smaller or larger workloads may change these values?
  • Basically, is 4 nodes the minimum or average? Is the instance type the minimum?
• Does Docker have any image/hardware requirements? Minimum/average requirements?
• Does Manual installation have any image/hardware requirements? Minimum/average requirements?
• Why don’t PostgreSQL supported versions match for Identity and Web Modeler? Aurora is missing from Identity, but what versions are supported?

[akeller]

Following up with Identity on Aurora missing from the Supported environments page - https://camunda.slack.com/archives/CRQAL5A1M/p1707846527383299

[akeller]

Blocked - pending feedback on overall messaging