Resolve "docs: create changelog"

Closes #42 (closed)

CHANGELOG.md

+# lydra.yunohost Changelog
+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).
+
+## [Unreleased]
+
+## [1.0.0] - date to be defined before release
+### Added
+- As we grew in terms of added features we have decided to transform this role into a collection.
+- You can now define symoblic links for `/etc/yunohost/` and `/var/www/`.
+- You can now create backups for Yunohost core and apps using `ynh_backup` role.
+
+### Changed
+- This role is now divided into four roles: `ynh_setup`, `ynh_config`, `ynh_apps`, `ynh_backup`. Each role has its own README so you can easily navigate between them and understand their purpose. 
+
+## [0.2.0] - date to be defined before release
+### Added
+- Adds the CHANGELOG.
+
+## [0.1.3] - 2021-11-09
+### Added
+- Two new tasks have been added for post-install apps feature. During Yunohost application setup you can now add additionnal scripts / configuration files which will be transferred to your Yunohost instance and run if necessary.
+
+### Changed
+- README explains how to use apps post-install feature.
+
+## [0.1.2] - 2021-10-27
+### Added
+- SMTP relay settings in Yunohost core can now be changed. This is a new task called `SMTP`.
+
+### Changed
+- README explains how to change SMTP relay values using specific variables.
+
+## [0.1.1] - 2021-10-21 [YANKED]
+### Fixed
+- fix default folder name into "defaults" to respect Ansible file architecture.
+
+## [0.1.0] - 2021-10-21
+### Added
+- The first release of the lydra.yunohost role. This role is a fork of two former Ansible roles : <https://github.com/TheRojam/ansible-yunohost> and <https://github.com/e-lie/ansible-yunohost>.
+- README is present in French and English as well as License info.