Fix #110: setReadableEncoding is wrong

Author: exoego

app/current/src/main/scala/io/scalajs/nodejs/stream/Stream.scala

@@ -163,8 +163,13 @@ sealed trait IReadable extends LegacyStream {
   def readable: Boolean = js.native
 
   @enableIf(io.scalajs.nodejs.internal.CompilerSwitches.gteNodeJs12)
+  @deprecated("Wrong name. Use readableEncoding", "0.9.1")
+  @JSName("readableEncoding")
   def setReadableEncoding: String = js.native
 
+  @enableIf(io.scalajs.nodejs.internal.CompilerSwitches.gteNodeJs12)
+  def readableEncoding: String = js.native
+
   @enableIf(io.scalajs.nodejs.internal.CompilerSwitches.gteNodeJs12)
   def readableEnded: Boolean = js.native