Description

Rewrites docs/getting-started/README.md from a minimal quick-start page into a complete hands-on tutorial using the air routes sample dataset.

The tutorial walks new users through Graph Explorer end-to-end:

1. Prerequisites and Launch — same Docker Compose setup, now with context about what you see on first load
2. Tour the UI — overview of the four main pages and the sidebar panels
3. Search for a Node — step-by-step search for airport "AUS" and adding it to the canvas
4. Expand Neighbors — double-click to discover connected airports
5. Filter the Graph — use Entities Filter to show/hide node types
6. Style Nodes — customize airport node color via the styling dialog
7. Switch to the Data Table — browse all nodes and send them to the graph
8. Next Steps — links to connection guides, deployment, configuration, and troubleshooting

Also updated the root README link from #try-it-out to #launch-graph-explorer to match the new heading.

Constraints followed

• Air routes / Gremlin-specific (the only bundled sample)
• Text-only (screenshots are a follow-up in Add screenshots to the getting-started tutorial #1719)
• Single page

Validation

Documentation-only change. Best validated by following the tutorial steps with a running air routes sample.

Related Issues

• Fixes Restructure getting-started page into a hands-on tutorial #1716
• Part of Update getting started docs #1097

Check List

• I confirm that my contribution is made under the terms of the Apache 2.0 license.
• I have verified pnpm checks passes with no errors.
• I have verified pnpm test passes with no failures.
• I have covered new added functionality with unit tests if necessary.
• I have updated documentation if necessary.