Add the known 'symlinks' issue to the release notes

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

installer/ReleaseNotes.md

@@ -8,6 +8,7 @@ These release notes describe issues specific to the Git for Windows release. The
 See [http://git-scm.com/](http://git-scm.com/) for further details about Git including ports to other operating systems. Git for Windows is hosted at [https://git-for-windows.github.io/](https://git-for-windows.github.io/).
 
 #Known issues
+* Special permissions (and Windows Vista or later) are required when cloning repositories with symbolic links, therefore support for symbolic links is disabled by default. Use `git clone -c core.symlinks=true <URL>` to enable it, see details [here](https://github.com/git-for-windows/git/wiki/Symbolic-Links).
 * If configured to use Plink, you will have to connect with [putty](http://www.chiark.greenend.org.uk/~sgtatham/putty/) first and accept the host key.
 * Some console programs interact correctly with MinTTY only when called through `winpty` (e.g. the Python console needs to be started as `winpty python` instead of just `python`).
 * [cURL](http://curl.haxx.se) uses `$HOME/_netrc` instead of `$HOME/.netrc`.