kernel-docs from home:ateixeira:xps13 project

需要 openSUSE Tumbleweed ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:ateixeira:xps13/openSUSE_Tumbleweed/home:ateixeira:xps13.repo
zypper refresh
zypper install kernel-docs