LOCAL images in IntelliSense in VS Code

I'm using TypeScript in VS Code. I'm using JSDoc for my comments, so IntelliSense often displays the comments as a tooltip. And I'm using Markdown to format those comments, including images. Mostly it works, but there's one problem. I only see images from an HTTP server. It will not display images from the local file system.

This is what I'd expect to see. However, this only works if I store the image on a web server.

This is what I see when I try to access a local file.

Here's a short version of the code behind those pictures. You can find the exact code, in context, here.

class IntelliSenseTest {
  /**
   * `to` and `from` assume that we are moving around the shape counter-clockwise,
   * i.e. the mathematically positive direction.
   * ![explanation of dots](./kite-dart-dots.png)
   */
  constructor(
  ) {}
}

export class Segment {
    /**
     * `to` and `from` assume that we are moving around the shape counter-clockwise,
     * i.e. the mathematically positive direction.
     * ![explanation of dots](https://raw.githubusercontent.com/TradeIdeasPhilip/penrose-tiling/master/docs/kite-dart-dots.png)
     */
    constructor(
    ) {}
    //..
  } 

The first example is the broken one. The second one displays the image properly but it uses a nasty workaround. I want to be able to save the image and the source file in the same directory. I want to be able to include them in the same commit. Is that possible?

Note: VS Code is able to display this file in its own window. And I can link directly to this local file in README.md. And we are looking at the exact same image, I just pushed my project to github.

You can see from this image or from github that the *.png and *.ts files are in the same directory.

Has anyone made this feature work? Any idea why it's not working for me?