Update advice

R/register-s3.R

@@ -25,7 +25,8 @@
 #' @section Usage in other packages:
 #' To avoid taking a dependency on vctrs, you copy the source of
 #' [`s3_register()`](https://github.com/r-lib/vctrs/blob/main/R/register-s3.R)
-#' into your own package. It is licensed under the permissive
+#' into your own package or with `usethis::use_standalone("r-lib/rlang", "s3-register")`.
+#' It is licensed under the permissive
 #' [unlicense](https://choosealicense.com/licenses/unlicense/) to make it
 #' crystal clear that we're happy for you to do this. There's no need to include
 #' the license or even credit us when using this function.