Reload, restart and exit i3WM

After modifying the config file, reload the config file by pressing $mod+Shift+c.

To restart i3 in place (and thus get into a clean state if there is a bug, or to upgrade to a newer version of i3) you can use $mod+Shift+r.

To cleanly exit i3 without killing your X server, you can use $mod+Shift+e.