Misc code cleanup (#3398)

* eframe README: explain how to enable copy/paste

* Implement Debug for a couple of structs

* Code cleanup

* Better docs

* profile ron serialization

* CI: Allow "exclude from changelog" as the only label

crates/eframe/src/epi/icon_data.rs

@@ -14,6 +14,15 @@ pub struct IconData {
     pub height: u32,
 }
 
+impl std::fmt::Debug for IconData {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("IconData")
+            .field("width", &self.width)
+            .field("height", &self.height)
+            .finish_non_exhaustive()
+    }
+}
+
 impl IconData {
     /// Convert into [`image::RgbaImage`]
     ///

crates/eframe/src/epi/mod.rs

@@ -308,6 +308,7 @@ pub struct NativeOptions {
     pub resizable: bool,
 
     /// On desktop: make the window transparent.
+    ///
     /// You control the transparency with [`App::clear_color()`].
     /// You should avoid having a [`egui::CentralPanel`], or make sure its frame is also transparent.
     pub transparent: bool,