This is self-explanatory.
I don’t want to allow data:
URIs for images, though.
This is marked “a11y” (accessibility) because Markdown would allow for a semantic-HTML in the description, which is more accessibile than just a preformatted block.
A preformatted block isn’t nessicarily inaccessible (which is why this is “v1.0” instead of “beta”), but it’s not as accessible as it could be.