gimp from home:RobinR1:gimp3 project

需要 openSUSE Tumbleweed ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:RobinR1:gimp3/openSUSE_Tumbleweed/home:RobinR1:gimp3.repo
zypper refresh
zypper install gimp