docs: add `run-fail` to semver check
docs: add `run-fail` to semver check

if the breaking change does not involve a compilation error but a change in runtime behaviour, you can add `run-fail` to the codeblock. The "before" code must return exit code 0, and the "after" code must be nonzero (like a panic).

eminence/cargo,rust-lang/cargo,nipunn1313/cargo,eminence/cargo,rust-lang/cargo,rustyhorde/cargo,rustyhorde/cargo,rustyhorde/cargo,rust-lang/cargo,eminence/cargo,rust-lang/cargo,eminence/cargo,nipunn1313/cargo,nipunn1313/cargo,rustyhorde/cargo,nipunn1313/cargo