Zenhub Helper per Jing You

When work with Zenhub github plugin on Github, it's a little inconvenience to list more issues due to the small workspace size especially on a small size of monitor. Zenhub helper is a companion of Zenhub plugin to hide/restore Github header/tabs by just 1-click on Zenhub helper's toolbar icon. It will easily maximize/restore Zenhub's working space and make project manager's life easier.