changelog: Catch up

CHANGELOG.md

@@ -16,6 +16,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 #### Removed
  - Removed type `secp256k1_scratch_space` and associated functions `secp256k1_scratch_space_create` and `secp256k1_scratch_space_destroy`, because that type is used nowhere else in the API.
 
+#### Changed
+ - Various improvements and changes to CMake builds. CMake builds remain experimental.
+   - Made API versioning consistent with GNU Autotools builds.
+   - Switched to `BUILD_SHARED_LIBS` variable for controlling whether to build a static or a shared library.
+   - Added `SECP256K1_INSTALL` variable for the controlling whether to install the build artefacts.
+ - Renamed asm build option `arm` to `arm32`. Use `--with-asm=arm32` instead of `--with-asm=arm` (GNU Autotools), and `-DSECP256K1_ASM=arm32` instead of `-DSECP256K1_ASM=arm` (CMake).
+
 ## [0.3.1] - 2023-04-10
 We strongly recommend updating to 0.3.1 if you use or plan to use Clang >=14 to compile libsecp256k1, e.g., Xcode >=14 on macOS has Clang >=14. When in doubt, check the Clang version using `clang -v`.