Update CHANGELOG.md for 4.64.0 (#4907)

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update CHANGELOG.md

* Update CHANGELOG.md

---------

Co-authored-by: Bogdan Gavril <bogavril@microsoft.com>

CHANGELOG.md

@@ -1,3 +1,12 @@
+4.64.0
+==========
+### New Features
+- Improved managed identity support for Azure ARC on Linux by adding file detection. See [Issue #4358](https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/issues/4358)
+- Added ROPC (Username/Password) support for confidential clients. See [Issue #3774](https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/issues/3774)
+
+### Bug Fixes
+- Resolved SHA2 issues that break custom claims during authentication flows. See [Issue #4868](https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/issues/4868)
+
 4.63.0
 ==========
 ### New Features