/usr/share/doc/libdbusmenu-glib-dev/README is in libdbusmenu-glib-dev 0.6.1-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libdbusmenu-glib-dev/../libdbusmenu-glib4/README
/usr/share/doc/libdbusmenu-glib-dev/../libdbusmenu-glib4/README