Updated changelog

changelog.markdown

@@ -61,4 +61,7 b' can override settings in the old setting'
 without at least one of them, while you can add any tags you want to it
 * [ADMIN] Cosmetic changes in the admin site. Adding and removing tags is much
 more simple now
-* Don't save tag's threads as a separate table, use aggregation instead
  No newline at end of file
+* Don't save tag's threads as a separate table, use aggregation instead
+
+# 2.3.0 Neiro
+* Image deduplication