Update changelog

Author: wereturtle

CHANGELOG.md

@@ -5,6 +5,14 @@ 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).
 
+## [2.1.1] - 2021-12-24
+
+### Fixed
+
+* Untitled documents are no longer created upon opening or closing a new, empty document.
+* Updated Chinese translation.
+* Fix compilation issue with Ubuntu 18.04.
+
 ## [2.1.0] - 2021-11-20
 
 #### Added