HTML in R / brilliant app - how to link (link / script / href) files on the server (javascript / html / css) in HTML?

When used includeHTML()

in R / shiny, how do I link to other files on the server from the included html page?

For example, if I want to <script>

create an external javascript, <link>

css file, or link a link <href>

to a local html file.

By default, other files in the shiny project directory don't seem to be visible from the html page that was included with includeHTML()