Update CHANGELOG.md

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed
+- "onPreprocessUrl" is now called for initial Tileset URL.
+
 ## [0.3.5] - 2022-01-06
 ### Added
 - `TilesRenderer.onTileVisibilityChange` callback.