https://thenextweb.com/dd/2018/10/16/github-launches-suggested-changes-to-make-it-easier-to-collaborate-within-pull-requests/

GitHub today announced Suggested Changes: a new feature that promises to make it easier to implement and action changes in pull requests. Here’s how it works.

Suppose you’re collaborating on a repository with an active pull request. A reviewer can look at that pull request, and if they see room for improvement, suggest a change to the code by leaving a comment. The author can then accept the suggestion with a single click.