[release] Add release notes for 2.14.2

Change-Id: If57db9e64e2e351acd5232830af3d2cc355e640e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/213460
Reviewed-by: Michael Thomsen <mit@google.com>

CHANGELOG.md

@@ -1,4 +1,25 @@
-## 2.14.0
+## 2.14.2 - 2021-09-16
+
+This is a patch release that fixes:
+
+- two dartdoc crashes (issues [dart-lang/dartdoc#2740][] and
+  [dart-lang/dartdoc#2755][]).
+- error messages when using the `>>>` operator on older language versions
+  (issue [#46886][]).
+- invalid `pubspec.lock` paths on Windows (issue [dart-lang/pub#3012][]).
+
+[dart-lang/dartdoc#2740]: https://github.com/dart-lang/dartdoc/issues/2740
+[dart-lang/dartdoc#2755]: https://github.com/dart-lang/dartdoc/issues/2755
+[#46886]: https://github.com/dart-lang/sdk/issues/46886
+[#45767]: https://github.com/dart-lang/sdk/issues/45767
+[dart-lang/pub#3012]: https://github.com/dart-lang/pub/issues/3012
+
+## 2.14.1 - 2021-09-09
+
+- Fixed an issue specific to the macOS ARM64 (Apple Silicon) SDK, where the Dart
+  commandline tools did not have the expected startup performance.
+
+## 2.14.0 - 2021-09-09
 
 ### Language