Dedicated mermaid preview tab (like markdown)

[bobbymannino]

Body

What are you proposing?

Same as markdown, svg, csv (in the future) it would be nice to have a 'mermaid: open preview' action that opens a new tab with just the preview of the .mmd file.

Why does this matter?

Some people do not write their mermaid code within a markdown file, so it's like having a live updating preview instead of using the CLI.

What becomes easier or possible?

For me its mostly about the live preview to see my changes as i'm writing them.

Possible approach

I'm aware that there is a mermaid crate, but i haven't look too much into it so not entirely sure.