CHANGELOG.md: Document this pull request

CHANGELOG.md

@@ -7,9 +7,14 @@
 - Fix the build for users without libsignal-protocol-c installed system-wide ([#31](https://github.com/gkdr/axc/pull/31)) (thanks, [@hartwork](https://github.com/hartwork)!)
 - The example code is runnable again, and some memory leaks ([#14](https://github.com/gkdr/axc/pull/14)) (thanks, [@fbrausse](https://github.com/fbrausse)!)
 - Compiler warnings for test files.
+- Add missing field `Requires.private:` to auto-generated pkg-config file `libaxc.pc` ([#32](https://github.com/gkdr/axc/pull/32)) (thanks, [@hartwork](https://github.com/hartwork)!)
+
+### Changed
+- Migrate build system from a Makefile to CMake ([#32](https://github.com/gkdr/axc/pull/32)) (thanks, [@hartwork](https://github.com/hartwork)!)
 
 ### Infrastructure
 - Cover Linux build by GitHub Actions CI ([#31](https://github.com/gkdr/axc/pull/31)) (thanks, [@hartwork](https://github.com/hartwork)!)
+- Cover Windows build by GitHub Actions CI using msys2 ([#32](https://github.com/gkdr/axc/pull/32)) (thanks, [@hartwork](https://github.com/hartwork)!)
 
 ## [0.3.6] - 2021-09-06
 ### Fixed