Add changelog entry

Author: simolus3

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 1.3.1
+
+* Update SQLite to 3.50.3.
+* Support receiving binary sync lines over HTTP when the Rust client is enabled.
+* Remove the experimental websocket transport mode.
+
 ## 1.3.0
 
 * Use version `0.4.2` of the PowerSync core extension, which improves the reliability