doc: update changelog with release details

CHANGELOG.md

@@ -4,6 +4,24 @@ 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).
 
+## [2.3.0](https://github.com/willofindie/vscode-cssvar/compare/v2.2.2...v2.3.0) - 2022-09-20
+### Features
+- [#73](https://github.com/willofindie/vscode-cssvar/issues/73) Add support for linting
+  - New setting added to this extension: `cssvar.mode` (similar syntax to eslint `rules` property)
+  - Set extension `mode` to `warn` or `error` to enable this new feature.
+-  Add test cases for diagnostics
+
+### Fixed
+-  Fixes definition and color providers with variable functions using spaces in between parenthesis.
+-  Minor fixes to debug logs.
+-  Fixes unit tests.
+
+
+### Doc
+-  Add emojis to readme accepteable on Marketplace doc as well.
+-  Segregate docs into sections, which can be read separately.
+
+
 ## [2.2.2](https://github.com/willofindie/vscode-cssvar/compare/v2.2.1...v2.2.2) - 2022-09-15
 ### Features
 - [#63](https://github.com/willofindie/vscode-cssvar/issues/63) Add support to fetch remote http file content