docs: add Europa, Callisto, and Charon basemap screenshots

[giswqs]

Summary

• Adds a third row of planetary basemap screenshots (Europa, Callisto, Charon) to the tables in README.md and docs/demos.md.
• The surrounding prose in both files already listed the Galilean moons and Charon among the covered bodies, so only the image tables needed updating. The demos captions carry the basemap name and attribution taken from packages/core/src/ellipsoids.ts.

Test plan

• All three image URLs return HTTP 200.
• Each screenshot was opened and verified to show the body it is labelled with.
• Captions match the basemap name and attribution fields in packages/core/src/ellipsoids.ts.
• Rendered tables look correct on the GitHub README and the published docs site.

Summary by CodeRabbit

• Documentation
  • Expanded the planetary basemaps demo gallery with new entries for Europa, Callisto, and Charon.
  • Added labeled image links and source credits for each newly displayed planetary basemap.
  • Updated the README and demo documentation to reflect the expanded gallery.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: a271a4c6-b522-48b9-9bfe-05e39179f9ca

📥 Commits

Reviewing files that changed from the base of the PR and between cc6615f and 3b01e87.

📒 Files selected for processing (2)

• README.md
• docs/demos.md

---

📝 Walkthrough

Walkthrough

The planetary basemap galleries in the README and demo documentation now include Europa, Callisto, and Charon images, labels, and source credits.

Changes

Planetary basemap gallery

Layer / File(s)	Summary
Add planetary basemap entries README.md, docs/demos.md	The planetary basemap tables now display Europa, Callisto, and Charon images with labels and source credits.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Possibly related PRs

• opengeos/GeoLibre#1451: Both changes update planetary basemap content in README.md and docs/demos.md.

Suggested reviewers: copilot

Poem

A rabbit hops past Europa’s light,
Callisto gleams in rows so bright.
Charon joins the gallery flow,
With labels set in tidy show.
“Three moons added!” the rabbit sings.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the added Europa, Callisto, and Charon basemap screenshots.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch docs/planetary-basemap-screenshots

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

No inline comments to post — this PR has no findings warranting them.

Code review

Reviewed the two-file docs diff (README.md, docs/demos.md) that adds a third row of planetary basemap screenshots (Europa, Callisto, Charon) to the existing image tables.

• Bugs: None found. High confidence — the new <tr> blocks mirror the existing table structure exactly (three <td width="33%"> image cells followed by a caption row), column counts match, and no markup is malformed.
• Security: None found. High confidence — image URLs point to the same files.opengeos.org host already used by every other row in these tables; no scripts, no user input, no secrets.
• Performance: Not applicable — static documentation markup only.
• Quality: None found. High confidence — alt text follows the established "GeoLibre globe view of X over a starfield backdrop" pattern used by sibling rows.
• CLAUDE.md: No violations. This change touches only README.md and docs/demos.md, which aren't governed by any of the repo-specific rules in CLAUDE.md (i18n, Whitebox catalogs, CSP allowlists, etc. all concern application source, not top-level docs).

Verification performed: cross-checked the demos.md captions ("Galileo / Voyager (NASA / JPL)" for Europa and Callisto, "New Horizons Mosaic (NASA / JHU APL / SwRI)" for Charon) against packages/core/src/ellipsoids.ts, which is called out in the PR description as the source of truth — both the basemap name fields and attribution strings (via usgsCredit(...)) match exactly for all three bodies.

[Copilot]

🟢 Ready to approve

The changes are isolated to documentation tables and appear consistent with existing table structure and the basemap naming/attribution used elsewhere in the docs.

This review doesn't count toward merge requirements. Sign up for the private preview to control whether Copilot approvals count.

Pull request overview

Adds additional planetary basemap screenshots to the documentation tables so the visual demos match the set of bodies already listed in the surrounding prose.

Changes:

• Adds a new third row of globe screenshots (Europa, Callisto, Charon) to the README planetary basemaps table.
• Adds the same screenshots to the docs demos page table, including captions with basemap name + source attribution.

File summaries

File	Description
README.md	Extends the planetary basemap screenshot grid with Europa/Callisto/Charon.
docs/demos.md	Extends the demos planetary basemap screenshot grid with Europa/Callisto/Charon and matching captions.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

We're testing this review assessment. Please use 👍 or 👎 to tell us if it's correct.

[github-actions]

🔍 Cloudflare PR preview

Item	Value
Site	https://78a16bca.geolibre-preview.pages.dev
Demo app	https://78a16bca.geolibre-preview.pages.dev/demo/
Commit	3b01e87

[github-actions]

🔍 GitHub Pages PR preview

Item	Value
Site	Deploy failed. See the job log.
Demo app	Unavailable
Commit	3b01e87