chore(stackable-operator): Separate some developer docs from CRD descriptions

[NickLarsenNZ]

The audience for doc-comments are quite different to those for the hosted CRD docs, so we should override CRD descriptions when they contain developer-level details.

Note

There are likely more changes required, but these are the few I noticed when bumping stackable-operator for druid-operator.

Description

Please add a description here. This will become the commit message of the merge request later.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added

[NickLarsenNZ]

It passes locally:

❯ pre-commit run --from-ref origin/main --to-ref HEAD
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
detect aws credentials...................................................Passed
detect private key.......................................................Passed
clippy...................................................................Passed
yamllint.............................................(no files to check)Skipped
markdownlint.........................................(no files to check)Skipped
ShellCheck v0.10.0...................................(no files to check)Skipped
Lint GitHub Actions workflow files...................(no files to check)Skipped
Lint Dockerfiles.....................................(no files to check)Skipped
.scripts/verify-crate-versions...........................................Passed
rustfmt..................................................................Passed