[Feedback]: Markdown Preview with Mermaid Diagram support

What problem are you trying to solve?

I often create some markdown files in my project, sometimes these are docs, sometimes content collection, sometimes blog posts, sometimes design skill artifacts, etc ...

The file preview panel lets me view the .md file, but not in a rendered preview way.

What would improve it?

• render markdown previews richly
• support Mermaid diagrams
• allow for wider view (currently, seems restricted width so hard to review complete file).
• ^^ in fact my prompt chat panel area is the one I need to be the narrowest as that is a prompt and responsive. the File list and preview or browser are the areas I likely need to be wider

What do you do today?

If I check in to GitHub, I view there as it provides the preview rendering I need - or I use a VSCode extension to review.

Ideally, th file preview could support other text formats too: md, css, yaml, toml.

Product area

Other

The issue names the file preview panel but no files, tests, or implementation entry points. Start by locating that panel and mapping the requested preview rendering, Mermaid support, wider layout, and additional text formats; done would require an agreed scope and working previews for the selected formats.