edited changelog

Edited CHANGELOG.md

- Realm database features.

Signed-off-by: Gabriele Ghio <gabriele.ghio@secomind.com>

CHANGELOG.md

@@ -5,6 +5,10 @@ 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]
+### Added
+- Added `Realm` entity to manipulate
+  all `realm` features (CRUD)
+
 ### Added
 - Add the `ASTARTE_INSTANCE_ID` env to allow sharing
   the database between multiple Astarte instances.