/usr/share/doc/libgtk-3-0/README is in libgtk-3-0 3.22.11-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgtk-3-0/../libgtk-3-common/README
/usr/share/doc/libgtk-3-0/../libgtk-3-common/README