update -Ypickle-write setting description

Author: bishabosha

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -437,5 +437,5 @@ private sealed trait YSettings:
 
   // Pipeline compilation options
   val YpickleJava: Setting[Boolean] = BooleanSetting("-Ypickle-java", "Pickler phase should compute pickles for .java defined symbols for use by build tools", aliases = List("-Yjava-tasty"))
-  val YpickleWrite: Setting[AbstractFile] = OutputSetting("-Ypickle-write", "directory|jar", "destination for generated .sig files containing type signatures.", NoAbstractFile, aliases = List("-Yearly-tasty"))
+  val YpickleWrite: Setting[AbstractFile] = OutputSetting("-Ypickle-write", "directory|jar", "destination for generated .tasty files containing possibly outline type signatures.", NoAbstractFile, aliases = List("-Yearly-tasty"))
 end YSettings