(Update the changelog: PyArrayDescr::new)

Author: aldanor

CHANGELOG.md

@@ -25,6 +25,8 @@
     - Added `get_field` to query fields of structured dtypes
     - Additional helper methods: `has_subarray`, `has_fields`, `is_native_byteorder`
     - Renamed `get_type` to `typeobj`
+    - `new` method, equivalent to invoking the constructor
+      of `np.dtype` ([#266](https://github.com/PyO3/rust-numpy/pull/266))
 
 - v0.15.1
   - Make arrays produced via `IntoPyArray`, i.e. those owning Rust data, writeable ([#235](https://github.com/PyO3/rust-numpy/pull/235))