Prepare v2.0.4

Signed-off-by: Sora Morimoto <sora@morimoto.io>

Author: smorimoto

CHANGELOG.md

@@ -8,6 +8,8 @@ and this project adheres to
 
 ## [unreleased]
 
+## [2.0.4]
+
 ### Changed
 
 - Set the upstream git url as a secondary repository on Windows.
@@ -336,7 +338,8 @@ that require it.
 
 - Initial release.
 
-[unreleased]: https://github.com/ocaml/setup-ocaml/compare/v2.0.3...HEAD
+[unreleased]: https://github.com/ocaml/setup-ocaml/compare/v2.0.4...HEAD
+[2.0.3]: https://github.com/ocaml/setup-ocaml/compare/v2.0.3...v2.0.4
 [2.0.3]: https://github.com/ocaml/setup-ocaml/compare/v2.0.2...v2.0.3
 [2.0.2]: https://github.com/ocaml/setup-ocaml/compare/v2.0.1...v2.0.2
 [2.0.1]: https://github.com/ocaml/setup-ocaml/compare/v2.0.0...v2.0.1