downloads a random image from Wikipedia, converts it to png, and renames it to random_image.png - will rewrite the image if one already exists.
Filters images:
| Filter | Current value | Meaning |
| ------------------ | ----------------: | ------------------------------------ |
| MIME type | JPEG / PNG / WebP | Rejects SVG, GIF, TIFF, etc. |
| Width | ≥ 300 px | Rejects very narrow/small images |
| Height | ≥ 300 px | Rejects very short/small images |
| Original file size | ≤ 20 MB | Avoids huge files |
| Thumbnail | 1280 px | Downloads a reasonably sized version |