[elixir] Explicitly set @moduledoc false when empty

[arvindpunk]

note: after learning a bit more about the structure of this repo and the 3.0.0 branch, I'll edit the issue to reflect the required changes in a day or two, apologies for the confusion

Description

For generated models, if a description is not present - moduledoc is set to empty string. As per style guide, when moduledoc is empty, explicitly set the module doc value to false.

style guide reference: https://github.com/christopheradams/elixir_style_guide#moduledoc-false

Swagger-codegen version

All versions. Pinning to issue creation date, 3.0.51.

Swagger declaration file content or url

openapi: 3.0.1
info:
  title: elixir-moduledoc
  version: 1.0.0
servers:
  - url: /
paths:
  /foo:
    get:
      operationId: foo
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: object
                properties:
                  bar:
                    type: string

Command line used for generation

Using the docker variant, but with language elixir and default options, would be able to replicate the issue.

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli generate \
    -i ./spec.yml \
    -g elixir

Steps to reproduce

Generate elixir client as shown above, produces a model file

# NOTE: This file is auto generated by OpenAPI Generator 7.0.1-SNAPSHOT (https://openapi-generator.tech).
# Do not edit this file manually.

defmodule ElixirModuledoc.Model.Foo200Response do
  @moduledoc """
  
  """

  @derive Jason.Encoder
  defstruct [
    :bar
  ]

  @type t :: %__MODULE__{
    :bar => String.t | nil
  }

  def decode(value) do
    value
  end
end

Related issues/PRs

N/A

Suggest a fix/enhancement

fix: add a condition to the moustache template for moduledoc

Expected generated file

# NOTE: This file is auto generated by OpenAPI Generator 7.0.1-SNAPSHOT (https://openapi-generator.tech).
# Do not edit this file manually.

defmodule ElixirModuledoc.Model.Foo200Response do
  @moduledoc false

  @derive Jason.Encoder
  defstruct [
    :bar
  ]

  @type t :: %__MODULE__{
    :bar => String.t | nil
  }

  def decode(value) do
    value
  end
end