clarify AsIs change in news

Author: teunbrand

NEWS.md

@@ -1,7 +1,8 @@
 # ggplot2 (development version)
 
-* Custom and raster annotation now respond to scale transformations 
-  (@teunbrand based on @yutannihilation's prior work, #3120)
+* Custom and raster annotation now respond to scale transformations, and can
+  use AsIs variables for relative placement (@teunbrand based on 
+  @yutannihilation's prior work, #3120)
 * When discrete breaks have names, they'll be used as labels by default 
   (@teunbrand, #6147).
 * The helper function `is.waiver()` is now exported to help extensions to work