## Changes
Based on @gaomeng1900's comprehensive testing feedback:
1. **Document known limitations**
- Slate.js and Draft.js do not work with synthetic events
- Draft.js: Cannot be supported via DOM manipulation (by design, unmaintained)
- Monaco/CodeMirror: Require direct JS instance access
2. **Clarify tested editors**
- Works: Quill, LinkedIn, simple contenteditable editors
- Does not work: Slate.js, Draft.js
3. **Preserve execCommand as fallback**
- execCommand works better for LinkedIn, Quill, and Draft.js
- Kept as commented fallback (deprecated API)
- Users can uncomment if synthetic events don't work
Co-authored-by: gaomeng1900 <gaomeng1900@users.noreply.github.com>