Changelog for 0.99.4

CHANGELOG.md

@@ -1,3 +1,24 @@
-# Version 0.99.3
+# Changelog
+
+All notable changes to async-std will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://book.async.rs/overview/stability-guarantees.html).
+
+## [Unreleased]
+
+# [0.99.4] - 2019-08-21
+
+## Changes
+
+- Many small changes in the book, mostly typos
+- Documentation fixes correcting examples
+- Now works with recent nightly with stabilised async/await (> 2019-08-21)
+
+# [0.99.3] - 2019-08-16
 
 - Initial beta release
+
+[Unreleased]: https://github.com/olivierlacan/keep-a-changelog/compare/v0.99.3...HEAD
+[0.99.4]: https://github.com/async-rs/async-std/compare/v0.99.3...v0.99.4
+[0.99.3]: https://github.com/async-rs/async-std/tree/v0.99.3