Add Unreleased section to changelog

Author: daniel-jones-dev

CHANGELOG.md

@@ -5,6 +5,15 @@ 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).
 
 
+## [Unreleased]
+### Added
+### Changed
+### Deprecated
+### Removed
+### Fixed
+### Security
+
+
 ## [1.2.1] - 2021-10-19
 ### Added
 * Add support for Python 3.10.
@@ -94,6 +103,7 @@ Version increased to avoid conflicts with old packages on PyPI.
 Initial version.
 
 
+[Unreleased]: https://github.com/DeepLcom/deepl-python/compare/v1.2.1...HEAD
 [1.2.1]: https://github.com/DeepLcom/deepl-python/compare/v1.2.0...v1.2.1
 [1.2.0]: https://github.com/DeepLcom/deepl-python/compare/v1.1.3...v1.2.0
 [1.1.3]: https://github.com/DeepLcom/deepl-python/compare/v1.1.2...v1.1.3