Move mremap CHANGELOG update to Unreleased-Added section

Author: sporksmith

CHANGELOG.md

@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased] - ReleaseDate
 ### Added
+- Added `mremap` (#[1306](https://github.com/nix-rust/nix/pull/1306))
 ### Changed
 ### Fixed
 ### Removed
@@ -29,7 +30,6 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   (#[1278](https://github.com/nix-rust/nix/pull/1278))
 - Made `unistd::fork` an unsafe funtion, bringing it in line with [libstd's decision](https://github.com/rust-lang/rust/pull/58059).
   (#[1293](https://github.com/nix-rust/nix/pull/1293))
-- Added `mremap` (#[1306](https://github.com/nix-rust/nix/pull/1306))
 ### Fixed
 ### Removed