Merge pull request #1082 from redboltz/release_600

Updated changelog.

Author: redboltz

CHANGELOG.md

@@ -1,4 +1,8 @@
-# 2023-03-02 version 6.0.0
+# 2023-07-08 version 6.0.0
+  * Remove dependency on boost in chrono.hpp (#1076)
+  * Add support for std::variant behavior (#1075)
+  * Fix msgpack::type::variant behavior to respect MessagePack format (#1071)
+  * Add rebind allocators (#1065)
 ## << breaking changes >>
   * Change CMake package name of C++ library to msgpack-cxx (#1054)
     Unified all C++ package, library, cmake, tarball name become msgpack-cxx.