Add example of prefix-less url in use_course()

Author: jennybc

R/course.R

@@ -28,6 +28,8 @@
 #' @examples
 #' \dontrun{
 #' ## bit.ly shortlink example
+#' ## should work with and without http prefix
+#' use_course("bit.ly/usethis-shortlink-example")
 #' use_course("http://bit.ly/usethis-shortlink-example")
 #'
 #' ## demo with a small CRAN package available in various places