/usr/lib/erlang/erts-9.2/doc is in erlang-doc 1:20.2.2+dfsg-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/erlang/erts-9.2/../../../share/doc/erlang-doc/erts-9.2/doc
/usr/lib/erlang/erts-9.2/../../../share/doc/erlang-doc/erts-9.2/doc