Automatically generate screenshots for all examples (#2379)

examples/custom_font/Cargo.toml

@@ -9,4 +9,6 @@ publish = false
 
 
 [dependencies]
-eframe = { path = "../../crates/eframe" }
+eframe = { path = "../../crates/eframe", features = [
+    "__screenshot", # __screenshot is so we can dump a ascreenshot using EFRAME_SCREENSHOT_TO
+] }

examples/custom_font/README.md

@@ -1,3 +1,7 @@
+Example of how to use custom fonts.
+
 ```sh
 cargo run -p custom_font
 ```
+
+![](screenshot.png)

examples/custom_font/src/main.rs

@@ -3,7 +3,10 @@
 use eframe::egui;
 
 fn main() {
-    let options = eframe::NativeOptions::default();
+    let options = eframe::NativeOptions {
+        initial_window_size: Some(egui::vec2(320.0, 240.0)),
+        ..Default::default()
+    };
     eframe::run_native(
         "egui example: custom font",
         options,