update_geom_defaults() added to news.md

Author: dkahle

NEWS.md

@@ -25,6 +25,8 @@
   (@teunbrand based on @clauswilke's suggestion #5051).
 * Fixed a regression in `Coord$train_panel_guides()` where names of guides were 
   dropped (@maxsutton, #5063)
+* `update_geom_defaults()` and `update_stat_defaults()` now return properly 
+  classed objects and have updated docs (@dkahle, #5146)
 
 # ggplot2 3.4.0
 This is a minor release focusing on tightening up the internals and ironing out