Prepare 0.4.0-alpha.1 release

Author: eldruin

CHANGELOG.md

@@ -7,14 +7,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
-### Added
-
-- Implement `embedded_hal::digital::blocking::IoPin` for `CdevPin` and `SysfsPin`
 
-## [v0.4.0-alpha.1] - 2021-09-27
+## [v0.4.0-alpha.1] - 2021-10-07
 
 ### Added
 
+- Implement `embedded_hal::digital::blocking::IoPin` for `CdevPin` and `SysfsPin`
 - `CountDown` implementation for `SysTimer`.
 - `Default` implementation for `SysTimer`.