Mention Bug Fix in release notes

A bug in the `notepad` support in conjunction with line wrapping
[was fixed](#218).

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

Author: dscho

ReleaseNotes.md

@@ -49,6 +49,7 @@ This package contains software from a number of other projects including Bash, z
 * Git Bash [works again in 32-bit Git for Windows](https://github.com/git-for-windows/MINGW-packages/commit/deb0395d031401ffe55024fb066267e2ea8d032b).
 * Git can now [access `git://` remotes again](https://github.com/git-for-windows/git/issues/1949).
 * The confusing descriptions of the PATH options in the installer [were clarified](https://github.com/git-for-windows/build-extra/pull/216).
+* A bug in the `notepad` support in conjunction with line wrapping [was fixed](https://github.com/git-for-windows/build-extra/pull/218).
 
 ## Changes since Git for Windows v2.19.1 (Oct 5th 2018)