Add exercise 2.1: suffixes

Both a built-in List and custom LIST implementation

src/main/scala/ChapterTwo.scala

@@ -0,0 +1,15 @@
+package org.jordanlewis.pfds
+
+object Suffixes {
+  def apply[A](xs: List[A]): List[List[A]] = xs match {
+    case Nil => Nil::Nil
+    case x::xs => (x::xs)::Suffixes(xs)
+  }
+}
+
+object CustomSuffixes {
+  def apply[A](xs: LIST[A]): LIST[LIST[A]] = xs match {
+    case NIL => new CONS(NIL, NIL)
+    case CONS(x, xs) => new CONS(new CONS(x, xs), CustomSuffixes(xs))
+  }
+}