Add "Unreleased" section to CHANGELOG

Author: adamwathan

CHANGELOG.md

@@ -5,6 +5,18 @@ All notable changes to this project 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://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- Dark mode variant (experimental) (#2279)
+- New `preserveHtmlElements` option for `purge` (#2283)
+- New `layers` mode for `purge` (#2288)
+
+### Deprecated
+
+- `conservative` purge mode, deprecated in favor of `layers`
+
 ## [1.7.6] - 2020-08-29
 
 ### Fixed
@@ -830,6 +842,7 @@ No release notes
 
 - Everything!
 
+[unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.6...HEAD
 [1.7.6]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.5...v1.7.6
 [1.7.5]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.4...v1.7.5
 [1.7.4]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.3...v1.7.4