Remove an erroneous comment from String.to_char_list's doc

Author: alco

lib/elixir/lib/string.ex

@@ -1385,10 +1385,6 @@ defmodule String do
 
  iex> String.to_char_list("æß")
  'æß'
-
- Notice that this function expects a list of integers representing
- UTF-8 codepoints. If you have a raw binary, you must instead use
- [the `:binary` module](http://erlang.org/doc/man/binary.html).
  """
  @spec to_char_list(t) :: char_list
  def to_char_list(string) when is_binary(string) do