update modal code comments

src/native/modal.rs

@@ -30,9 +30,8 @@ pub use crate::style::modal::StyleSheet;
 /// }
 ///
 /// let modal = Modal::new(
-/// false,
 /// Text::new("Underlay"),
-/// Text::new("Overlay"),
+/// Some(Text::new("Overlay")),
 /// )
 /// .backdrop(Message::CloseModal);
 /// ```
@@ -45,7 +44,7 @@ where
 {
  /// The underlying element.
  underlay: Element<'a, Message, Renderer>,
- /// The content of the [`ModalOverlay`](ModalOverlay).
+ /// The optional content of the [`ModalOverlay`](ModalOverlay).
  overlay: Option<Element<'a, Message, Renderer>>,
  /// The optional message that will be send when the user clicked on the backdrop.
  backdrop: Option<Message>,
@@ -70,10 +69,9 @@ where
  /// overlying content.
  ///
  /// It expects:
- /// * if the overlay of the date picker is visible.
  /// * the underlay [`Element`] on which this [`Modal`](Modal)
  /// will be wrapped around.
- /// * the content [`Element`] of the [`Modal`](Modal).
+ /// * the optional overlay [`Element`] of the [`Modal`](Modal).
  pub fn new(
  underlay: impl Into<Element<'a, Message, Renderer>>,
  overlay: Option<impl Into<Element<'a, Message, Renderer>>>,