Closes: [BS-3358](https://linear.app/affine-design/issue/BS-3358/remark-callout-plugin)
Closes: [BS-3247](https://linear.app/affine-design/issue/BS-3247/callout-markdown-adapter-适配)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added support for callout blocks in Markdown, enabling recognition and conversion of callout syntax (e.g., `[!emoji]`) to and from block structures.
- **Bug Fixes**
- Improved handling to distinguish callout blocks from regular blockquotes and paragraphs during Markdown processing.
- **Tests**
- Introduced comprehensive tests for callout block serialization, deserialization, and plugin behavior to ensure correct Markdown handling.
- **Chores**
- Added a new dependency for Markdown AST traversal.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->