Mention New Feature in release notes

Existing Git Credential Manager
for Windows users are now [automatically
upgraded](#305)
to [Git Credential Manager
Core](https://github.com/microsoft/git-credential-manager-core/).

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

ReleaseNotes.md

@@ -48,6 +48,7 @@ This package contains software from a number of other projects including Bash, z
 * Comes with [libfido2 v1.5.0](https://github.com/Yubico/libfido2/releases/tag/1.5.0).
 * Comes with [OpenSSH v8.4p1](https://www.openssh.com/txt/release-8.4).
 * Comes with [Git Credential Manager Core v2.0.252.766](https://github.com/microsoft/git-credential-manager-core/releases/tag/v2.0.252-beta).
+* Existing Git Credential Manager for Windows users are now [automatically upgraded](https://github.com/git-for-windows/build-extra/pull/305) to [Git Credential Manager Core](https://github.com/microsoft/git-credential-manager-core/).
 
 ### Bug Fixes