route_mappings.go
func (a *App) ServeFiles(p string, root http.FileSystem) {
	path := path.Join(a.Prefix, p)
	a.filepaths = append(a.filepaths, path)

	h := stripAsset(path, a.fileServer(root), a)
	a.router.PathPrefix(path).Handler(h)
}
func (a *App) ServeFiles(p string, root http.FileSystem) {
	path := path.Join(a.Prefix, p)
	a.filepaths = append(a.filepaths, path)

	h := stripAsset(path, a.fileServer(root), a)
	a.router.PathPrefix(path).Handler(h)
}
// ServeFiles maps an path to a directory on disk to serve static files.
// Useful for JavaScript, images, CSS, etc...
/*
	a.ServeFiles("/assets", http.Dir("path/to/assets"))
*/