Feature request: accessibility

[stereobooster]

Motivating example

https://mermaid.js.org/config/accessibility.html

  graph LR
      accTitle: This is the accessible title
      accDescr: This is an accessible description
      A[Identify Big Decision] --> B{Make Big Decision}
      B --> D[Be done]

Explanation

In Mermaid one can add accTitle and accDescr, which then can be used like this

<svg
  aria-labelledby="chart-title-mermaid-1668725057758"
  aria-describedby="chart-desc-mermaid-1668725057758"
  xmlns="http://www.w3.org/2000/svg"
  width="100%"
  id="mermaid-1668725057758"
>
  <title id="chart-title-mermaid-1668725057758">This is the accessible title</title>
  <desc id="chart-desc-mermaid-1668725057758">This is an accessible description</desc>
</svg>

For SVG it would just work, but for images (server side rendering) it would need to be exposed, for example, like this:

const { content, title, description } = render(config)

And as long as we are here it could also expose width and height for generated image

const { width, height, content, title, description } = render(config)