Same key params are not overwritten to the last defined

Editor assessment

The described behavior — same-key params should be overwritten by the last definition — is stated from the user's perspective, which helps, but the phrasing 'overwritten to the last defined' is awkward and takes a moment to parse; 'last definition should win' would be crisper. `fix` is correctly chosen and the `Co-authored-by:` footer is well-formed `token: value` metadata. There is no scope and no body: for a parsing-semantics bug, a short example (input params, expected output) would have been the perfect changelog content and is missing. Length, mood, and punctuation are acceptable.