Update changelog

Author: adamwathan

CHANGELOG.md

@@ -20,6 +20,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add new utilities for `grid-auto-columns` and `grid-auto-rows` ([#2531](https://github.com/tailwindlabs/tailwindcss/pull/2531))
 - Rename `{u}-max-content` and `{u}-min-content` utilities to `{u}-max` and `{u}-min` in experimental extended spacing scale ([#2532](https://github.com/tailwindlabs/tailwindcss/pull/2532))
 
+## [1.8.13] - 2020-10-09
+
+### Fixed
+
+- Support defining colors as closures even when opacity variables are not supported ([#2536](https://github.com/tailwindlabs/tailwindcss/pull/2515))
+
 ## [1.8.12] - 2020-10-07
 
 ### Fixed
@@ -947,7 +953,8 @@ No release notes
 
 - Everything!
 
-[unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.12...HEAD
+[unreleased]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.13...HEAD
+[1.8.12]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.12...v1.8.13
 [1.8.12]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.11...v1.8.12
 [1.8.11]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.10...v1.8.11
 [1.8.10]: https://github.com/tailwindlabs/tailwindcss/compare/v1.8.9...v1.8.10