qa: Updates CHANGELOG

Adds entries for each of 0.1.0 and 0.2.0, and creates a new entry for
the changes in 0.2.1.

CHANGELOG.md

@@ -2,12 +2,72 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 0.1.0 - TBD
+## 0.2.1 - 2019-01-10
 
 ### Added
 
+- Adds documentation of all capabilities.
+
+- Adds `EventDispatcherFactory`, which also requires the second `$serviceName`
+  argument during invocation. The argument is assumed to be the class name of an
+  `EventDispatcherInterface` implementation, and this class is instantiated
+  using the value of the `ListenerProviderInterface` service.
+
+- Adds `ListenerShouldQueue`, a marker interface indicating that the listener
+  can be safely deferred for asynchronous invocation.
+
+### Changed
+
+- Registers all listener providers and all event dispatchers as container services.
+
+### Deprecated
+
 - Nothing.
 
+### Removed
+
+- Nothing.
+
+### Fixed
+
+- Nothing.
+
+## 0.2.0 - 2019-01-09
+
+### Added
+
+- Adds support for the 0.7.0 version of the PSR-14 specification.
+
+### Changed
+
+- `ErrorTaskProcessor` was renamed to `ErrorEmittingDispatcher`.
+
+- `TaskProcessor` was renamed to `EventDispatcher`.
+
+- The various `ListenerProviderInterface` implementations were updated to use
+  `object` typehints, instead of `EventInterface` (as the latter is no longer part
+  of the spec).
+
+### Deprecated
+
+- Nothing.
+
+### Removed
+
+- `Notifier` was removed, as it is no longer part of the specification.
+
+- `StoppableTaskTrait` was removed, as it is now part of fig/event-dispatcher-util.
+
+### Fixed
+
+- Nothing.
+
+## 0.1.0 - 2018-08-15
+
+### Added
+
+- Adds support for the 0.3.0 version of the PSR-14 specification.
+
 ### Changed
 
 - Nothing.