Update changelog

Author: adamwathan

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Nothing new yet!
+
+## [1.8.0] - 2020-09-04
+
 ### Added
 
 - Dark mode variant (experimental) ([#2279](https://github.com/tailwindlabs/tailwindcss/pull/2279))
@@ -850,6 +854,7 @@ No release notes
 - Everything!
 
 [unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.6...HEAD
+[1.8.0]: https://github.com/tailwindlabs/tailwindcss/compare/v1.7.6...v1.8.0
 [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