[DOC] - auto-generate CRD reference

[andrewfulton9]

Preliminary Checks

• This issue is not a question, feature request, RFC, or anything other than a bug report. Please post those things in GitHub Discussions: https://github.com/nebari-dev/nebari/discussions

Summary

Add a make docs target (or equivalent) to nebari-operator that generates a NicApp CRD reference in markdown from the CRD schema, so nebari-docs can pull it at build time without hand-edited pages drifting from the code.

Related: nebari-dev/nebari-docs#665

Work

Generate NicApp CRD reference markdown

• Tooling: crd-ref-docs (or controller-gen with a doc plugin) invoked via a make docs target
• Source: the CRD definition produced by controller-gen from the operator's Go types
• Output: a single markdown file with a field-by-field reference table and annotated examples, emitted to a known path (e.g. docs/nicapp-crd-reference.md)

Wire into CI

• Add a CI step that runs the generator and fails the build if:
  • the generator errors, or
  • the output is stale (generated content does not match the committed file — enforce with git diff --exit-code)

Acceptance criteria

• make docs (or equivalent) generates NicApp CRD reference markdown from the CRD schema
• Generated output is committed to the repo at a stable path that nebari-docs can reference
• CI fails if the generator errors or if generated content is out of sync with the CRD types
• No hand-edited CRD field documentation — all field descriptions come from Go type comments/markers

Notes

• nebari-docs will pull this generated file at build time (via git submodule, released artifact, or a sync script — the mechanism is decided on the nebari-docs side)
• Field descriptions shown in the reference come from // +kubebuilder:validation markers and Go doc comments on the struct fields — make sure those are present and accurate before the generator runs

[andrewfulton9]

Closing as this was already completed in #87