Ensure that a file-based HTML dependency (from the htmltools package) can be
served over Shiny's HTTP server. This function works by using
addResourcePath to map the HTML dependency's directory to a
URL.
createWebDependency(dependency)A single HTML dependency object, created using
htmlDependency. If the src value is named, then
href and/or file names must be present.
A single HTML dependency object that has an href-named element
in its src.