message: Use `fill_rectangle` for cursor in `game_of_life`
diff: @@ -339,13 +339,9 @@ mod grid {
  let cell =
  Cell::at(self.project(cursor_position, frame.size()));
  - let interaction = Path::rectangle(
  + frame.fill_rectangle(
  Point::new(cell.j as f32, cell.i as f32),
  Size::UNIT,
  - );
  -
  - frame.fill(
  - &interaction,
  Color {
  a: 0.5,
  ..Color::BLACK
  