src.DesignNotes

design.md explains why this crate is shaped as it is, and its Rust blocks had drifted out of the crate they describe: one named an Error variant nobody wrote. Compiling them is what keeps a rationale honest about the thing it is rationalising.

Every block in that file is one, an indented block included: rustdoc reads indentation as a fence and a fence with no language as Rust. A block quoting tmux source or terminal output needs a text tag, or the gate reports the crate as one that does not compile.