Expand description
Detects specific markdown syntax that’s different between pulldown-cmark 0.9 and 0.11.
This is a mitigation for old parser bugs that affected some real crates’ docs. The old parser claimed to comply with CommonMark, but it did not. These warnings will eventually be removed, though some of them may become Clippy lints.
https://github.com/rust-lang/rust/pull/121659#issuecomment-1992752820