docs: update README for Nextflow plugin registry compliance

[adamrtalbot]

Summary

• Rename "Quick Start" → "Get Started" to match the registry's required section names
• Use absolute GitHub URL for the notification screenshot so it renders on the registry
• Add "Examples" section with bot configuration snippets (bot-only, no webhooks)

The Nextflow plugin registry requires README.md to include Summary, Get Started, Examples, and License sections. The releasePlugin Gradle task already sends the README as the documentation field — these changes ensure it passes registry validation and renders correctly.

[claude]

Code Review

Documentation: Changes are accurate and well-targeted. Renaming "Quick Start" → "Get Started" and switching to an absolute image URL are the right fixes for registry compliance.

Examples: The two new bot snippets are clear and practical. Minor gap: no webhook example is included, even though webhooks are mentioned as a configuration option in the existing README. Consider adding a brief webhook snippet or noting it's covered via the gallery link.

Tests: No tests needed — this is a documentation-only change.

UX: The new examples section flows naturally and the gallery link at the end is a good call-to-action.

Overall: Changes are minimal and purposeful. Approved with the suggestion to consider a webhook snippet in Examples to match the existing UX copy that mentions webhooks.