Fix omission in CHANGELOG.md for PR #199.

- Add mention of new `stream` and `substream` commands.

- Mention new `&seq` pattern.

Author: okamsn

CHANGELOG.md

@@ -28,9 +28,20 @@ This document describes the user-facing changes to Loopy.
   of each loop cycle and that it does not modify its variable
   until the specified cycle ([#202]).
 
+### Destructuring Improvements
+
+- Added a `&seq` pattern, which can use `seq.el` ([#199]).
+
+### Command Improvements
+
+- Added new `substream` and `stream` commands, which works like `conses` but for
+  steams as implemented by `stream.el` in ELPA ([#199]).
+
+
 [#195]: https://github.com/okamsn/loopy/pull/195
 [#196]: https://github.com/okamsn/loopy/pull/196
 [#197]: https://github.com/okamsn/loopy/pull/197
+[#199]: https://github.com/okamsn/loopy/pull/199
 [#202]: https://github.com/okamsn/loopy/pull/202
 
 ## 0.12.2