Add pre-publish-send-email hook example script
Add pre-publish-send-email hook example script

This example script file shows how a pre-publish-send-email hook can
validate a patch emails before they are sent.

Signed-off-by: Stefan Hajnoczi <484520986196e4a799496429ce8a499eb6488adb@gmail.com>

stefanha/git-publish,stefanha/git-publish