Mention Bug Fix in release notes

The documentation of Git for Windows' several config files [was
improved](git-for-windows/git#1165).

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

Author: dscho

ReleaseNotes.md

@@ -40,6 +40,10 @@ This package contains software from a number of other projects including Bash, z
 * Comes with [Git Credential Manager v1.10.0](https://github.com/Microsoft/Git-Credential-Manager-for-Windows/releases/tag/v1.10.0).
 * Comes with [OpenSSH 7.5p1](https://www.openssh.com/releasenotes.html#7.5p1).
 
+### Bug Fixes
+
+* The documentation of Git for Windows' several config files [was improved](https://github.com/git-for-windows/git/pull/1165).
+
 ## Changes since Git for Windows v2.12.2(2) (April 5th 2017)
 
 ### New Features