markdown: Improve table cell alignment (#53465)

## Summary

Markdown preview tables kept text pinned to the top of a row when a
neighboring cell contained a taller image. This made mixed
text-and-image tables look unbalanced and inconsistent with common
editor behavior. This change makes table text stay visually centered
within taller rows so Markdown tables are easier to scan and match
expected rendering more closely.

## Before / After

| Before | After |
| --- | --- |
| <img width="849" height="869" alt="Screenshot 2026-04-08 at 19 55 50"
src="https://github.com/user-attachments/assets/b3751bff-3750-4ca1-8997-6f5265e4d291"
/> | <img width="898" height="734" alt="Screenshot 2026-04-08 at 21 47
31"
src="https://github.com/user-attachments/assets/d853c0a1-800c-4a2a-aec9-e0ef08453fa7"
/> |

## References
Inspired by comparing this with VS Code preview
<img width="1286" height="878" alt="Screenshot 2026-04-08 at 21 54 06"
src="https://github.com/user-attachments/assets/8dbbfe28-9980-4012-94f1-1b5b3503065b"
/>

Release Notes:

- Improved Markdown preview table cells to vertically center content in
tall rows and respect column alignment from the table header.

---------

Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>
e6b8b30e22David Alecrim committed on 5/7/2026, 12:26:13 PM· committed by GitHubparent59daeba
2 files changedLine totals unavailable