docs(crd): fix NiFi authorization usage guide link (usage-guide -> usage_guide)

[MukundaKatta]

Summary

The `spec.clusterConfig.authorization` CRD description links to the NiFi authorization usage guide using a hyphenated path:

```
https://docs.stackable.tech/home/stable/nifi/usage-guide/security#authorization
```

That URL 404s. Every other usage-guide link in this repo (`authentication`, `custom-components`, `extra-volumes`, `security`) uses `usage_guide` with an underscore, matching the actual docs path (`docs/modules/nifi/pages/usage_guide/security.adoc`).

Changes:

• `rust/operator-binary/src/crd/mod.rs`: fixed the rustdoc link used to generate the CRD description.
• `extra/crds.yaml`: applied the same fix to the checked-in generated CRD so it stays in sync.
• `CHANGELOG.md`: added an "Unreleased / Fixed" entry referencing this issue.

Closes #841

Testing

Documentation-only change. Verified:

• new path `https://docs.stackable.tech/home/stable/nifi/usage_guide/security#authorization\` resolves to the NiFi authorization section;
• all other `usage_guide` links in the repo already use the underscore form.

[stackable-cla]

All committers have signed the CLA.

[xeniape]

LGTM thank you for opening a PR on this and fixing the broken link! :)

Just a small change request regarding the Changelog entry: The numbers actually reference the PRs not the issues

[xeniape]

Could you also sign the CLA please? We need that to be able to accept the contribution ❤️ the link is in one of the above messages.

[MukundaKatta]

@xeniape Applied your changelog suggestion — pushed c9c24f5 reordering the PR link references ([#916], [#921], [#922], [#924]) as you had them.

On the CLA — I'll get it signed and post back once it's done. Thanks for the review!

[xeniape]

Seems like the branch needs to resolve a small merge conflict, I can do that as well but didn't want to just meddle in your PR. Once that's done, I can approve 👍

[MukundaKatta]

@xeniape rebased onto latest main. The CHANGELOG conflicts came from [#903], [#922], [#916], [#921] all landing while this sat — resolved by slotting the ### Fixed section under ### Changed and keeping all five PR references in numerical order. The actual fix (usage-guide -> usage_guide in rust/operator-binary/src/crd/mod.rs + regenerated extra/crds.yaml) is unchanged. Ready to merge.

[MukundaKatta]

Thanks @xeniape — already addressed that in the rebase I pushed yesterday. The changelog now references [#924] (the PR) instead of [#841] (the original issue). See the ### Fixed entry at the top of CHANGELOG.md. Ready for merge whenever convenient.