[Add] some collections examples.

Author: Mauricio Serna

collections.exs

@@ -0,0 +1,12 @@
+# Lists
+
+list1 = ["foo", :bar, 42]
+list2 = [42, :bar]
+
+IO.puts list1 -- list2
+
+# Tuples
+
+tuple = {3.14, "Canada", "Colombia"}
+
+IO.puts Enum.join(Tuple.to_list(tuple))