docs(changelog): 1.0.0 release

CHANGELOG.md

@@ -5,10 +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).
 
-## [Unreleased]
 
+## [1.0.0] - 2023-10-13
+### Changed
 - POTENTIALLY BREAKING: remove nvim-treesitter dependency.
-  It is advised to be on at least Neovim v0.9.0
+  It is advised to be on at least Neovim v0.9.0 to use this
+  plugin without nvim-treesitter.
+  The [tree-sitter parser for Haskell](https://github.com/tree-sitter/tree-sitter-haskell)
+  still has to be installed.
 
 ## [0.8.5] - 2023-09-02
 ### Changed