add changeset, remove changelog

Author: Brian Chen

.changeset/rare-rabbits-grab.md

@@ -0,0 +1,6 @@
+---
+'@firebase/firestore': minor
+'@firebase/firestore-types': minor
+---
+
+Added support for `set()` with merge options when using `FirestoreDataConverter`.

packages/firestore/CHANGELOG.md

@@ -1,8 +1,6 @@
 # Unreleased
 - [fixed] Fixed an issue that may have prevented the client from connecting 
   to the backend immediately after a user signed in.
-- [fixed] Added support for using `set()` with merge options when using
-  `FirestoreDataConverter`.
 
 # Released
 - [changed] All known failure cases for Indexed-related crashes have now been