I added one bullet to CHANGELOG.md, under ## [Unreleased] → ### Added, for the --lang option: "--lang option that selects the greeting language (en default, es, fr)". It follows the style of the existing bullets, and I changed nothing else. The check grep -q -- '--lang' CHANGELOG.md passes.
None of the open pull requests touch CHANGELOG.md, so I don't expect conflicts with them. I didn't check that the wording matches the actual --lang behavior in the code.