Desugar scala code snippet 23 in chapter 3.4 (#297)

Co-authored-by: Anton Macmillan-Parks <anton.macmillanparks@clearscore.com>

src/content/3.4/code/scala/snippet23.scala

@@ -1,11 +1,8 @@
-def words: String => List[String] =
-  _.split("\\s+").toList
-
 def process: String => Writer[String, List[String]] =
   s => {
-    import bindSyntax._
-    for {
-      upStr <- upCase(s)
-      _ <- tell("toWords ")
-    } yield words(upStr)
+    upCase(s).flatMap { upStr =>
+      tell("toWords ").flatMap { _ =>
+        writerMonad.pure(words(upStr))
+      }
+    }
   }