xxdiff from home:aeszter project

需要 15.6 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:aeszter/15.6/home:aeszter.repo
zypper refresh
zypper install xxdiff

需要 15.5 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:aeszter/15.5/home:aeszter.repo
zypper refresh
zypper install xxdiff

需要 15.4 ，用 root 執行：

zypper addrepo https://download.opensuse.org/repositories/home:aeszter/15.4/home:aeszter.repo
zypper refresh
zypper install xxdiff