message: Simplify `Canvas` example in documentation
diff: @@ -78,7 +78,7 @@ pub use text::Text;
  /// impl Drawable for Circle {
  /// fn draw(&self, frame: &mut Frame) {
  /// // We create a `Path` representing a simple circle
  -/// let circle = Path::new(|p| p.circle(frame.center(), self.radius));
  +/// let circle = Path::circle(frame.center(), self.radius);
  ///
  /// // And fill it with some color
  /// frame.fill(&circle, Fill::Color(Color::BLACK));
  