Docs no longer say Geoms don't have setup_params() method (#4161)

* doc no longer says no setup_params() method for geom

* added back everything but last sentence

Author: burchill

R/geom-.r

@@ -14,9 +14,7 @@ NULL
 #' Compared to `Stat` and `Position`, `Geom` is a little
 #' different because the execution of the setup and compute functions is
 #' split up. `setup_data` runs before position adjustments, and
-#' `draw_layer()` is not run until render time, much later. This
-#' means there is no `setup_params` because it's hard to communicate
-#' the changes.
+#' `draw_layer()` is not run until render time, much later.
 #'
 #' To create a new type of Geom object, you typically will want to
 #' override one or more of the following: