I used [pdfmake](https://www.npmjs.com/package/pdfmake) to implement an
"export as PDF" feature, and I am happy to share with you!
This should fix#13577, fix#8846, and fix#13959.
A showcase:
[Getting
Started.pdf](https://github.com/user-attachments/files/24013057/Getting.Started.pdf)
Although it might miss rendering some properties currently, it can
evolve in the long run and provide a more native experience for the
users.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
- Experimental "Export to PDF" option added to the export menu (behind a
feature flag)
- PDF export supports headings, paragraphs, lists, code blocks, tables,
images, callouts, linked documents and embedded content
* **Chores**
- Added PDF rendering library and consolidated PDF utilities
- Feature flag introduced to control rollout
* **Tests**
- Comprehensive unit tests added for PDF content rendering logic
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: DarkSky <darksky2048@gmail.com>
DarkSky
