Fork the hack-night (https://github.com/rubyloco/hack-night.git) on github to your account (ala https://github.com/shadowbq/hack-night.git)
Using the shell download your clone, create/switch to your topic branch, add your submodule, commit it, push it to your account.
git clone https://github.com/shadowbq/hack-night.git
cd hack-night/
git remote add upstream https://github.com/rubyloco/hack-night.git
git fetch upstream
git checkout -b shadowbq-loco-flag upstream/master