docs: option to build image based on distroless

[WaterWhisperer]

What's Changed in this PR

docs for #7240 related issue: #2217

Checklist

• [ ] Please confirm that all corresponding versions of the documents have been revised.
• [ ] Please ensure that the content in sidebars.ts matches the current document structure when you changed the document structure.
• [ ] This change requires follow-up update in localized docs.

[sunng87]

I think distroless variant is not in our CI pipeline (we just have a Dockerfile in the repo) so the docker hub repo is not available. Correct me if i was wrong.

[WaterWhisperer]

I think distroless variant is not in our CI pipeline (we just have a Dockerfile in the repo) so the docker hub repo is not available. Correct me if i was wrong.

Sorry I may have misunderstood the https://github.com/GreptimeTeam/greptimedb/pull/7240#pullrequestreview-3485972433, thanks for the clarification, so where is it appropriate to update the relevant information?

[sunng87]

I think we don't need to update user facing docs for this.