doc(indexeddb): update changelog

Signed-off-by: Michael Goldenberg <[email protected]>

Author: mgoldenberg

crates/matrix-sdk-indexeddb/CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased] - ReleaseDate
 
+### Features
+
+- Expose implementations of `EventCacheStore` and `MediaStore` and add a
+  composite type for initializing all stores with a single function - i.e.,
+  `IndexeddbStores::open`. Additionally, allow feature flags for each of the
+  stores to be used independent of and in combination with the others.
+  ([#5946](https://github.com/matrix-org/matrix-rust-sdk/pull/5946))
+
 ### Bug Fixes
 
 - Ensure that encrypted tests are run with a `StoreCipher`. This happened to reveal tests which fail in an