feat(infographic-markdown): add new plugin for JS render to Markdown

- Add infographic_markdown.py (English) and infographic_markdown_cn.py (Chinese)
- AI-powered infographic generator using AntV library
- Renders SVG on frontend and embeds as Markdown Data URL image
- Supports 18+ infographic templates (lists, charts, comparisons, etc.)

Docs:
- Add plugin README.md and README_CN.md
- Add docs detail pages (infographic-markdown.md)
- Update docs index pages with new plugin
- Add 'JS Render to Markdown' pattern to plugin development guides
- Update copilot-instructions.md with new advanced development pattern

Version: 1.0.0

docs/plugins/actions/index.md

@@ -77,6 +77,16 @@ Actions are interactive plugins that:
 
     [:octicons-arrow-right-24: Documentation](summary.md)
 
+-   :material-image-text:{ .lg .middle } **Infographic to Markdown**
+
+    ---
+
+    AI-powered infographic generator that renders SVG and embeds it as Markdown Data URL image.
+
+    **Version:** 1.0.0
+
+    [:octicons-arrow-right-24: Documentation](infographic-markdown.md)
+
 </div>
 
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