Add parentheses to mentions of binned_scale in scale-alpha and scale-viridis documentation (#4735)

Author: damonbayer

R/scale-alpha.r

@@ -5,7 +5,7 @@
 #' `scale_alpha()` is an alias for `scale_alpha_continuous()` since
 #' that is the most common use of alpha, and it saves a bit of typing.
 #'
-#' @param ... Other arguments passed on to [continuous_scale()], [binned_scale],
+#' @param ... Other arguments passed on to [continuous_scale()], [binned_scale()],
 #'   or [discrete_scale()] as appropriate, to control name, limits,
 #'   breaks, labels and so forth.
 #' @param range Output range of alpha values. Must lie between 0 and 1.

R/scale-viridis.r

@@ -9,7 +9,7 @@
 #' @inheritParams scales::gradient_n_pal
 #' @inheritParams continuous_scale
 #' @param ... Other arguments passed on to [discrete_scale()],
-#' [continuous_scale()], or [binned_scale] to control name, limits, breaks,
+#' [continuous_scale()], or [binned_scale()] to control name, limits, breaks,
 #'   labels and so forth.
 #' @param aesthetics Character string or vector of character strings listing the
 #'   name(s) of the aesthetic(s) that this scale works with. This can be useful, for