message: Center window in `game_of_life` example
diff: @@ -9,6 +9,7 @@ use iced::executor;
  use iced::pick_list::{self, PickList};
  use iced::slider::{self, Slider};
  use iced::time;
  +use iced::window;
  use iced::{
  Align, Application, Checkbox, Clipboard, Column, Command, Container,
  Element, Length, Row, Settings, Subscription, Text,
  @@ -19,6 +20,10 @@ use std::time::{Duration, Instant};
  pub fn main() -> iced::Result {
  GameOfLife::run(Settings {
  antialiasing: true,
  + window: window::Settings {
  + position: window::Position::Centered,
  + ..window::Settings::default()
  + },
  ..Settings::default()
  })
  }
  