Add two possible solutions to the ascii-printable exercise

strings/stringsandbinaries1.exs

@@ -0,0 +1,10 @@
+defmodule StringsAndBinaries do
+  def ascii_printable?(char_list) do
+    List.ascii_printable?(char_list)
+  end
+
+  def custom_ascii_printable?(char_list) do
+    # every character in char list must between 20hex 32 and 126
+    Enum.all?(char_list, &( 32 <= &1 and &1 <= 126))
+  end
+end