iex> Base36.encode(13)
"D"

iex> Base36.encode(31)
"V"

iex> Base36.encode(274)
"7M"

iex> Base36.decode!("95")
329

iex> Base36.decode!("TETRAPYRROLE")
3871237878461204546

iex> Base36.decode!("Кириллица")
** (ArgumentError) non-alphabet digit found: а
    (base36) lib/base36.ex:2: Base36.decode_char/1
    (base36) lib/base36.ex:2: Base36.decode/2

iex> Base36.decode("42")
{:ok, 146}

iex> Base36.decode("ERLANG")
{:ok, 892869676}

iex> Base36.decode("lower")
:error