/usr/lib/mono/monodoc/monodoc.dll is in monodoc-base 3.2.8+dfsg-10.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/mono/monodoc/../gac/monodoc/1.0.0.0__0738eb9f132ed756/monodoc.dll
/usr/lib/mono/monodoc/../gac/monodoc/1.0.0.0__0738eb9f132ed756/monodoc.dll