URL-encode the image paths in Markdown so that images with filenames (#41788)

Closes https://github.com/zed-industries/zed/issues/41786

Release Notes:

- markdown preview: Fixed an issue where path urls would not be parsed
correctly when containing URL-encoded characters

<img width="1680" height="1126"
alt="569415cb-b3e8-4ad6-b31c-a1898ec32085"
src="https://github.com/user-attachments/assets/7de8a892-ff01-4e00-a28c-1c5e9206ce3a"
/>
146e754f73aohanhongzhi committed on 11/7/2025, 1:02:40 PM· committed by GitHubparent278fe91
3 files changedLine totals unavailable