fix unvendor example

Author: pachadotdev

R/unvendor.R

@@ -15,7 +15,7 @@
 #' cpp_vendor(dir)
 #'
 #' # unvendor the cpp11 headers from the directory
-#' unvendor_cpp11(dir)
+#' cpp_unvendor(dir)
 #'
 #' list.files(file.path(dir, "inst", "include", "cpp11"))
 #'