Enrich mount function with paddle state

game.ex

def mount(_session, socket) do
  state = %{
    unit: @unit,
    tick: @tick,
    paddle: %{
      width: @paddle_length * @unit,
      height: @paddle_height * @unit,
      # Coordinates of the box surrounding the paddle
      left: Helpers.coordinate(@paddle_left, @unit),
      top: Helpers.coordinate(@paddle_top, @unit),
      right: Helpers.coordinate(@paddle_left + @paddle_length, @unit),
      bottom: Helpers.coordinate(@paddle_top + @paddle_height, @unit),
      # Misc
      direction: :stationary,
      speed: @paddle_speed,
      length: @paddle_length
    }
  }

  # ...other code below
end