message: Minor doc update to graphics::get_screen_coordinates()
diff: @@ -583,6 +583,9 @@ pub fn get_renderer_info(ctx: &Context) -> GameResult<String> {
  /// Returns a rectangle defining the coordinate system of the screen.
  /// It will be `Rect { x: left, y: bottom, w: width, h: height }`
  +///
  +/// If the Y axis increases downwards, the `height` of the Rect
  +/// will be negative.
  pub fn get_screen_coordinates(ctx: &Context) -> Rect {
  ctx.gfx_context.screen_rect
  }
  