Now that #5 is merged and I can see it in the browser, I wonder if it would be possible to improve the image borders, like maybe:
```html <img ... class="... border border-secondary rounded" /> ```
Or something like that? It will probably make the one (@kugel-) with the "screenshot missing" image look terrible, but seems like it would improve the other thumbnails, especially light themes on the light page background. Eventually I'll get around to making a screenshot for the one that's missing.
What do you think?