docs: add how-to for transferring Helm charts with OCM (#751)

#### What this PR does / why we need it

Adds a how-to guide for transferring component versions containing Helm
chart resources (`helm/v1` access type) between OCI registries using the
OCM CLI. Covers the `--upload-as localBlob` and `--upload-as
ociArtifact` options.

Related to
open-component-model/open-component-model#1846

#### Which issue(s) this PR is related to

Related to
open-component-model/open-component-model#1846 (comment)

#### Type of content

- [ ] Tutorial (`getting-started/` or `tutorials/`)
- [x] How-to Guide (`how-to/`)
- [ ] Explanation / Concept (`concepts/`)
- [ ] Reference (`reference/`)
- [ ] Other (infrastructure, config, fixes)

#### Checklist

- [x] I have read and followed the [Contributing
Guide](https://github.com/open-component-model/ocm-website/blob/main/CONTRIBUTING.md)
- [x] All commands/code snippets are tested and can be copy-pasted

#### Test

```bash
#!/bin/zsh

set -e

REGISTRY="${REGISTRY:-ghcr.io/matthiasbruns/ocm-tutorials}"
COMPONENT="ocm.software/podinfo"
VERSION="6.9.1"

CTF_DIR=$(mktemp -d)
echo "CTF archive: $CTF_DIR"

pause() {
  echo "\n>>> Next: $1"
  echo "--- Press Enter to continue ---"
  read
}

# Step 1: Create constructor.yaml
cat <<EOF > constructor.yaml
components:
- name: ${COMPONENT}
  version: ${VERSION}
  provider:
    name: ocm.software
  resources:
  - name: podinfo
    version: ${VERSION}
    type: helmChart
    access:
      type: helm/v1
      helmRepository: https://stefanprodan.github.io/podinfo
      helmChart: podinfo-${VERSION}.tgz
EOF

echo "Created constructor.yaml"

pause "Add component version to CTF archive"

# Step 2: Add component version to CTF
./ocm add cv \
  --repository "ctf::${CTF_DIR}" \
  --constructor constructor.yaml \
  --skip-reference-digest-processing

echo "Component version added to CTF"

pause "Transfer with --upload-as ociArtifact"

# Step 3: Transfer as ociArtifact
./ocm transfer cv \
  --copy-resources \
  --upload-as ociArtifact \
  "ctf::${CTF_DIR}//${COMPONENT}:${VERSION}" \
  "${REGISTRY}"

echo "Transfer complete (ociArtifact)"

pause "Verify: get component version from registry"

# Step 4: Verify component version
./ocm get cv "${REGISTRY}//${COMPONENT}:${VERSION}"

pause "Verify: inspect component descriptor to find imageReference"

# Step 5: Inspect component descriptor to find imageReference
./ocm get cv "${REGISTRY}//${COMPONENT}:${VERSION}" -o yaml

pause "Verify: download the chart resource"

# Step 6: Download the chart resource
rm -rf ./downloaded
./ocm download resource \
  "${REGISTRY}//${COMPONENT}:${VERSION}" \
  --identity "name=podinfo,version=${VERSION}" \
  --output ./downloaded

echo "\nDownloaded to ./downloaded:"
ls -la ./downloaded

# Cleanup
pause "Clean up CTF archive"
rm -rf "${CTF_DIR}"
echo "Removed ${CTF_DIR}"
echo "\nDone."

```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Documentation**
* Added a detailed how-to for transferring Helm-chart-backed component
versions between OCI registries via the CLI, including prerequisites,
step-by-step workflow, verification, storage modes, cross-registry
examples, and relevant commands.

* **Chores**
* Expanded repository configuration wordlist with two additional entries
to recognize more terms.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Matthias Bruns <git@matthiasbruns.com> ef663ee

Author: github-actions[bot]