changelog: Add entries for MP4 changes

Author: Serial-ATA

CHANGELOG.md

@@ -9,13 +9,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Added
 - **ID3v2**: Support for "RVA2", "OWNE", "ETCO", and "PRIV" frames through
              `id3::v2::{RelativeVolumeAdjustmentFrame, OwnershipFrame, EventTimingCodesFrame, PrivateFrame}`
+- **MP4**:
+  - `Atom::into_data`
+  - `Atom::merge`
 
 ## Changed
 - **ID3v2**:
   - For spec compliance, `Id3v2Tag::insert` will now check for frames that are only meant to appear
     in a tag once and remove them. Those frames are: "MCDI", "ETCO", "MLLT", "SYTC", "RVRB", "PCNT", "RBUF", "POSS", "OWNE", "SEEK", and "ASPI".
   - `Id3v2Tag::remove` will now take a `FrameId` rather than `&str`
   - `FrameId` now implements `Into<Cow<'_, str>>`, making it possible to use it in `Frame::new`
+- **MP4**:
+  - `Ilst::remove` will now return all of the removed atoms
+  - `Ilst::insert_picture` will now combine all pictures into a single `covr` atom
 
 ## [0.15.0] - 2023-07-11