/usr/share/proton-0.14.0/docs/api-cpp/jquery.js is in libqpid-proton-cpp8-dev-doc 0.14.0-5.1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/proton-0.14.0/docs/api-cpp/../../../javascript/jquery/jquery.min.js