message: CHANGELOG.md: Add "Fixed" line for issue
  This is not related to the PR / branch.
  I'm just slipping it in here for convenience,
  since the CHANGELOG.md didn't exist back then.
diff: @@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  ## [NEXT]
  ### Fixed
  - Fixed wasteful course data usage #654 via specialized course model interfaces.
  +- Fixed a broken documentation link #583.
  ### Security
  - Fixed multiple severe course related security issues #594, #653.
  