Add Event::Key::repeat that is set to true if the event is a repeat (#2435)

* Add `Event::Key::repeat` that is set to `true` if the event is a repeat

* Update changelog

* Improve docstring

crates/egui-winit/src/lib.rs

@@ -594,6 +594,7 @@ impl State {
                 self.egui_input.events.push(egui::Event::Key {
                     key,
                     pressed,
+                    repeat: false, // egui will fill this in for us!
                     modifiers: self.egui_input.modifiers,
                 });
             }