Resources
The resources/ directory stores auxiliary files that the script loads at runtime, such as CommandBar menu and toolbar XML layouts.
Files in resources/ are accessed with Host.Url() using the package:// scheme and the package ID declared in metainfo.xml:
var menuUrl = Host.Url("package://" + PackageID + "/resources/menu.xml");
The returned Host.Url object can be passed to file reading methods like Host.IO.openTextFile() or Host.IO.XmlTree(). See Host.Url and Host.IO for full surfaces.