markdown: Add HTML `img` tag support (#36700)

Closes #21992

<img width="1406" height="1184" alt="Screenshot 2025-08-21 at 18 09 24"
src="https://github.com/user-attachments/assets/5f14a0d8-c4d9-48ad-b10d-fadfaca258ea"
/>

Code example:

```markdown
# Html Tag
<img src="https://picsum.photos/200/300" alt="Description of image" />

# Html Tag with width and height
<img src="https://picsum.photos/200/300" alt="Description of image" width="100" height="200" />

# Html Tag with style attribute with width and height
<img src="https://picsum.photos/200/300" alt="Description of image" style="width: 100px; height: 200px" />

# Normal Tag
![alt text](https://picsum.photos/200/300)
```

Release Notes:

- Markdown: Added HTML `<img src="/some-image.svg">` tag support
1ca5e84019Remco Smits committed on 8/31/2025, 8:43:24 AM· committed by GitHubparentd80f132
5 files changedLine totals unavailable