Warning on PowResetPassword docs generation

[holsee]

When leveraging PowResetPassword:

defmodule Foo.Users.User do
  use Foo.Schema
  use Pow.Ecto.Schema

  use Pow.Extension.Ecto.Schema,
    extensions: [PowInvitation, PowResetPassword]

  ...
end

Warning on docs generation:

> mix docs

Generating docs...
warning: documentation references "PowResetPassword.Ecto.Schema.reset_password_changeset/2" but it is hidden
  apps/foo/lib/foo/users/user.ex:1: Foo.Users.User.pow_reset_password_changeset/2

Erlang: 23.x
Elixir: 1.11
ExDoc: 0.23