bug#62536: 30.0.50; Can we add """ ... """ electric pair in elixir, just like python

[牟 桐]

Hi!

In elixir, the docs in src are like this:

``` elixir-ts-mode

defmodule Foo do

  @moduledoc """

  Foo-related functions.

  ## Examples

      iex> Foo.sum(1, 2)

      3

  """

  @doc """

  Calculate the sum of two numbers.

  """

  def sum(a, b), do: a + b

end

```

In python-mode, input the continious triple quotes, it will insert the

left quotes when electric-pair-mode is on.

python-mode did it here:

https://github.com/emacs-mirror/emacs/blob/bfa3500c3c6e4df58978e84753718cd5358c06fb/lisp/progmodes/python.el#L6599-L6607

https://github.com/emacs-mirror/emacs/blob/bfa3500c3c6e4df58978e84753718cd5358c06fb/lisp/progmodes/python.el#L6637-L6639

This behavior is also very common in elixir, so can we add this to

elixir-ts-mode? thx