When building the `doc` with `asciidoctor`, `asciidoctor` complains about
a nested code block in a callout list. This is a really dirty solution to
restore the callout list to function properly. There is a minimal visual
sideeffect; the *immitated* codeblock has no overall greyish background.
Instead the individual lines have it.
Note: When building this patch with `asciidoc` the background is totally
gone but the font is still monospaced.
Signed-off-by: nalla <nalla@hamal.uberspace.de>