REST Docs Dependencies

Steps to reproduce

This patch removes the inclusion of a lot of unnecessary resources
originating from a time where this module did hold more than the REST
documentation. All of the few necessary resources are now included.

This patch also includes an update for the now unsupported version 1.x
of jQuery, updated to v3.3.1.

Finally, this separates JavaScript and CSS to make using some security
features like Content-Security-Policy headers possible.

Fixed and reviewed


Lars Kiesow


Lars Kiesow