Update version in README

Author: SimoTod@users.noreply.github.com

CHANGELOG.md

@@ -5,6 +5,8 @@ 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]
+
+## [v1.2.2] - 2021-05-04
 ### Fixed
 - [`$component`]: x-for was not working correctly when looping on a property from the parent scope (i.e. `x-for="item in $parent.items"`).