add .arcconfig file

Summary: Signed-off-by: Gustavo Carneiro <gcarneiroa@hotmail.com>

Reviewers: tcanabrava, andreagenor, #kde_games, patrickelectric

Reviewed By: andreagenor, patrickelectric

Subscribers: aacid, cfeck, kde-games-devel

Tags: #kde_games

Differential Revision: https://phabricator.kde.org/D20187