message: Document fixes to the CLI argument parsing
diff: @@ -167,6 +167,12 @@ is based on [Keep a Changelog](https://keepachangelog.com).
  - In some edge cases, actors failed to shut down properly when hosting a stream
  source (#1076). The handshake process for a graceful shutdown has been fixed.
  - Fixed a compiler error on Clang 10 (#1077).
  +- Setting lists and dictionaries on the command line now properly overrides
  + default values and values from configuration files instead of appending to
  + them (#942).
  +- Using unquoted strings in command-line arguments inside lists now works as
  + expected. For example, `--foo=abc,def` is now equivalent to
  + `--foo=["abc", "def"]`.
  ## [0.17.4] - 2019-02-08
  