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,

crates/eframe/src/native/file_storage.rs

@@ -130,6 +130,7 @@ fn save_to_disk(file_path: &PathBuf, kv: &HashMap<String, String>) {
             let mut writer = std::io::BufWriter::new(file);
             let config = Default::default();
 
+            crate::profile_scope!("ron::serialize");
             if let Err(err) = ron::ser::to_writer_pretty(&mut writer, &kv, config)
                 .and_then(|_| writer.flush().map_err(|err| err.into()))
             {