Add a release note (feature)

MinGit [now supports running `git
difftool`](#550).

Signed-off-by: gitforwindowshelper[bot] <gitforwindowshelper-bot@users.noreply.github.com>

ReleaseNotes.md

@@ -47,6 +47,7 @@ This package contains software from a number of other projects including Bash, z
 * Comes with [PCRE2 v10.43](https://github.com/PCRE2Project/pcre2/releases/tag/pcre2-10.43).
 * Comes with [GNU Privacy Guard v2.4.5](https://github.com/gpg/gnupg/releases/tag/gnupg-2.4.5).
 * Comes with [Git LFS v3.5.1](https://github.com/git-lfs/git-lfs/releases/tag/3.5.1).
+* MinGit [now supports running `git difftool`](https://github.com/git-for-windows/build-extra/pull/550).
 
 ## Changes since Git for Windows v2.43.0 (November 20th 2023)