[#1335] Added CHANGELOG.md entry.

CHANGELOG.md

@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - OStatus: Extract RSS functionality
 - Deprecated `User.Info` embedded schema (fields moved to `User`)
 - Store status data inside Flag activity
+- Deprecated (reorganized as `UserRelationship` entity) User fields with user AP IDs (`blocks`, `mutes`, `muted_reblogs`, `muted_notifications`, `subscribers`).
 <details>
   <summary>API Changes</summary>