The edX documentation team no longer maintains a change log for each guide. For a weekly summary of platform changes, refer to the EdX Release Notes on the docs.edx.org website.
For information about changes made to the edX documentation set, the edx-documentation repository on GitHub provides a complete record.
For older changes, see 2015년의 변화 로그 (김연봉 테스트) or Change Log for 2013 through 2014.