update changelog

crates/cust/CHANGELOG.md

@@ -2,6 +2,17 @@
 
 Notable changes to this project will be documented in this file.
 
+## Unreleased
+
+- `DeviceSlice` is represented as a slice again, but as `[()]` instead of `[T]`.
+- Reimplemented `Index` and `IndexMut` for `DeviceSlice` and removed `DeviceSlice::index`.
+- Methods that returned `DeviceSlice` by value now return references:
+    - `DeviceSlice::from_raw_parts`
+    - `DeviceSlice::from_raw_parts_mut`
+    - `DeviceSliceIndex::index`
+    - `DeviceSliceIndex::get_unchecked`
+- Added `DeviceSliceIndex::index_mut` and `DeviceSliceIndex::get_unchecked_mut`.
+
 ## 0.3.1 - 2/11/22
 
 No changes, updated to cust_derive 0.2 to fix a bug.