Changelog entry

Author: MarkDuckworth

firebase-firestore/CHANGELOG.md

@@ -1,5 +1,5 @@
 # Unreleased
-
+* [feature] Add support for the VectorValue type. [#6154](//github.com/firebase/firebase-android-sdk/pull/6154)
 
 # 25.0.0
 * [feature] Enable queries with range & inequality filters on multiple fields. [#5729](//github.com/firebase/firebase-android-sdk/pull/5729)